/* css/styles.css v6.1 (Bug-fixed, enhanced recommendations) */
:root {
    /* Color Palette */
    --primary: #007bff;
    --primary-hover: #0056b3;
    --primary-light: rgba(0, 123, 255, 0.1);
    --secondary: #6c757d;
    --secondary-hover: #5a6268;
    --danger: #dc3545;
    --danger-hover: #c82333;
    --success: #28a745;
    --warning: #ffc107;

    /* Light Theme */
    --bg-light: #f0f4f8;
    --card-bg-light: rgba(255, 255, 255, 0.65);
    --card-border-light: rgba(255, 255, 255, 0.8);
    --text-light: #212529;
    --text-muted-light: #6c757d;
    --heading-light: #0059b3;

    /* Dark Theme */
    --bg-dark: #0d1117;
    --card-bg-dark: rgba(22, 27, 34, 0.7);
    --card-border-dark: rgba(139, 148, 158, 0.2);
    --text-dark: #c9d1d9;
    --text-muted-dark: #8b949e;
    --heading-dark: #58a6ff;
    
    /* Universal Properties */
    --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.1);
    --border-radius: 16px;
    --transition-speed: 0.3s;
    
    font-size: 16px;
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 100%;
}

body {
    font-family: 'Inter', 'Noto Sans Kannada', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-light);
    line-height: 1.6;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
    padding-bottom: 0;
    overflow-x: hidden;
}

body.dark {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}

/* --- LOADING SCREEN --- */
.loading-screen {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 9999;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}
body.dark .loading-screen { background: var(--bg-dark); }
.loading-screen.fade-out { opacity: 0; visibility: hidden; pointer-events: none; }
.loading-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    width: min(520px, 92vw);
}
.running-man {
    animation: runBounce 0.6s ease-in-out infinite alternate;
}
@keyframes runBounce {
    0% { transform: translateY(0); }
    100% { transform: translateY(-10px); }
}
.rm-larm { animation: armSwingL 0.4s ease-in-out infinite alternate; transform-origin: 58px 38px; }
.rm-rarm { animation: armSwingR 0.4s ease-in-out infinite alternate; transform-origin: 58px 38px; }
.rm-lleg { animation: legSwingL 0.4s ease-in-out infinite alternate; transform-origin: 58px 55px; }
.rm-rleg { animation: legSwingR 0.4s ease-in-out infinite alternate; transform-origin: 58px 55px; }
@keyframes armSwingL { 0% { transform: rotate(-15deg); } 100% { transform: rotate(15deg); } }
@keyframes armSwingR { 0% { transform: rotate(15deg); } 100% { transform: rotate(-15deg); } }
@keyframes legSwingL { 0% { transform: rotate(-20deg); } 100% { transform: rotate(20deg); } }
@keyframes legSwingR { 0% { transform: rotate(20deg); } 100% { transform: rotate(-20deg); } }
.rm-drop { animation: dropFloat 1.5s ease-in-out infinite; }
.rm-drop-1 { animation-delay: 0s; }
.rm-drop-2 { animation-delay: 0.5s; }
.rm-drop-3 { animation-delay: 1s; }
@keyframes dropFloat {
    0%, 100% { opacity: 0.1; transform: translateY(0); }
    50% { opacity: 0.4; transform: translateY(-8px); }
}
.loading-text {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
}
.loading-text span {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading-light);
}
body.dark .loading-text span { color: var(--heading-dark); }
.loading-text small {
    font-size: 0.85rem;
    color: var(--text-muted-light);
}
body.dark .loading-text small { color: var(--text-muted-dark); }
.loading-bar {
    width: min(260px, 100%);
    height: 4px;
    background: var(--card-border-light);
    border-radius: 4px;
    overflow: hidden;
}
body.dark .loading-bar { background: var(--card-border-dark); }
.loading-bar-fill {
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, var(--primary), #58a6ff, var(--primary));
    border-radius: 4px;
    animation: loadBarFill 5s linear forwards;
}
@keyframes loadBarFill {
    0% { width: 0; }
    40% { width: 60%; }
    70% { width: 85%; }
    100% { width: 100%; }
}
.loading-log {
    width: 100%;
    max-width: 520px;
    padding: 0.85rem 0.95rem;
    border: 1px solid rgba(0, 89, 179, 0.18);
    border-radius: 12px;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(244, 249, 255, 0.88));
    box-shadow: 0 10px 24px rgba(0, 89, 179, 0.08);
    font-family: Consolas, "SFMono-Regular", "Liberation Mono", Menlo, monospace;
}
body.dark .loading-log {
    border-color: rgba(88, 166, 255, 0.16);
    background:
        linear-gradient(180deg, rgba(18, 24, 33, 0.94), rgba(13, 17, 23, 0.9));
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.28);
}
.loading-log-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.65rem;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--heading-light);
}
body.dark .loading-log-header { color: var(--heading-dark); }
.loading-log-indicator {
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    background: #17c964;
    box-shadow: 0 0 0 4px rgba(23, 201, 100, 0.14);
    animation: loadingPulse 1.2s ease-in-out infinite;
}
@keyframes loadingPulse {
    0%, 100% { opacity: 0.75; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.12); }
}
.loading-log-stream {
    min-height: 10rem;
    max-height: 10rem;
    overflow-y: auto;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    gap: 0.38rem;
    scrollbar-width: none;
}
.loading-log-stream::-webkit-scrollbar {
    display: none;
}
.loading-log-line {
    display: grid;
    grid-template-columns: 6.8rem 3.8rem 1fr;
    gap: 0.7rem;
    align-items: start;
    font-size: 0.73rem;
    line-height: 1.45;
    color: var(--text-light);
    opacity: 0;
    transform: translateY(6px);
    animation: loadingLogReveal 0.24s ease forwards;
}
body.dark .loading-log-line { color: var(--text-dark); }
@keyframes loadingLogReveal {
    to { opacity: 1; transform: translateY(0); }
}
.loading-log-time {
    color: var(--text-muted-light);
    white-space: nowrap;
}
body.dark .loading-log-time { color: var(--text-muted-dark); }
.loading-log-level {
    display: inline-flex;
    justify-content: center;
    min-width: 3.2rem;
    padding: 0.08rem 0.38rem;
    border-radius: 999px;
    font-weight: 700;
    letter-spacing: 0.04em;
    background: rgba(0, 123, 255, 0.1);
    color: var(--heading-light);
}
body.dark .loading-log-level {
    background: rgba(88, 166, 255, 0.14);
    color: var(--heading-dark);
}
.loading-log-line.level-ready .loading-log-level {
    background: rgba(40, 167, 69, 0.14);
    color: #1a7f37;
}
body.dark .loading-log-line.level-ready .loading-log-level {
    background: rgba(46, 160, 67, 0.18);
    color: #3fb950;
}
.loading-log-message {
    min-width: 0;
    word-break: break-word;
}

/* --- THEMATIC BACKGROUND ANIMATION --- */
.bg-decoration {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.wave {
    background: rgba(0, 123, 255, 0.05);
    border-radius: 50%;
    position: absolute;
    width: 200vw;
    height: 200vw;
    bottom: -150vw;
    left: -50vw;
    animation: wave 25s infinite linear;
}
.wave.wave-2 {
    animation-delay: -5s;
    animation-duration: 30s;
    opacity: 0.7;
}
@keyframes wave {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.bubble {
    position: absolute;
    bottom: -150px;
    width: 40px;
    height: 40px;
    background: rgba(0, 123, 255, 0.1);
    border-radius: 50%;
    animation: bubble-rise 20s infinite ease-in;
}
.bubble.bubble-1 { left: 10%; animation-duration: 22s; animation-delay: 0s; }
.bubble.bubble-2 { left: 40%; width: 25px; height: 25px; animation-duration: 30s; animation-delay: 5s; }
.bubble.bubble-3 { left: 75%; width: 50px; height: 50px; animation-duration: 18s; animation-delay: 2s; }

@keyframes bubble-rise {
    0% { transform: translateY(0) translateX(0); opacity: 1; }
    50% { transform: translateX(50px); }
    100% { transform: translateY(-120vh) translateX(100px); opacity: 0; }
}

/* --- HEADER --- */
.main-header {
    padding: 1.5rem clamp(1rem, 5vw, 4rem);
    max-width: 1800px;
    margin: 0 auto;
}
.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo-section { display: flex; align-items: center; gap: 1rem; }
.logo-icon { font-size: clamp(2.5rem, 6vw, 3.5rem); }
h1 { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 700; color: var(--heading-light); }
.subtitle { font-size: clamp(1rem, 2vw, 1.2rem); color: var(--text-muted-light); }
body.dark h1 { color: var(--heading-dark); }
body.dark .subtitle { color: var(--text-muted-dark); }

.header-controls { display: flex; align-items: center; gap: 1rem; }
.control-btn {
    border: none;
    background: none;
    cursor: pointer;
    transition: transform var(--transition-speed) ease;
    padding: 0.5rem;
    color: var(--text-light);
}
body.dark .control-btn { color: var(--text-dark); }
.control-btn:hover { transform: scale(1.1); }
#langToggle {
    font-size: clamp(0.9rem, 1.5vw, 1rem);
    font-weight: 600;
    border: 1px solid var(--card-border-light);
    border-radius: 8px;
    padding: 0.6rem 1rem;
    background: var(--card-bg-light);
}
body.dark #langToggle {
    border-color: var(--card-border-dark);
    background: var(--card-bg-dark);
}
#themeToggle { font-size: clamp(1.5rem, 3vw, 1.75rem); }

/* --- MAIN LAYOUT --- */
.main-grid {
    display: grid;
    grid-template-columns: minmax(400px, 1.2fr) 2fr;
    gap: clamp(1.5rem, 3vw, 2.5rem);
    max-width: 1800px;
    margin: 0 auto;
    padding: 1rem clamp(1rem, 5vw, 4rem) 2rem;
}
.section-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.section-icon { font-size: 2rem; }
h2 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    color: var(--heading-light);
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--primary);
}
body.dark h2 { color: var(--heading-dark); }

/* --- GLASS CARD STYLING --- */
.glass-card {
    background: var(--card-bg-light);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--border-radius);
    border: 1px solid var(--card-border-light);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    transition: background var(--transition-speed) ease;
    margin-bottom: 1.5rem;
}
body.dark .glass-card {
    background: var(--card-bg-dark);
    border: 1px solid var(--card-border-dark);
}

/* --- PARAMETER SECTION (LEFT COLUMN) --- */
.parameter-fieldset { border: none; padding: 0; margin: 0; box-shadow: none; background: transparent; }
.parameter-fieldset legend {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--heading-light);
    margin-bottom: 1rem;
    padding: 0;
}
body.dark .parameter-fieldset legend { color: var(--heading-dark); }

.params-grid { display: grid; gap: 1rem; }
.param-item {
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    align-items: center;
    gap: 0 1rem;
    padding: 1rem;
    background: var(--bg-light);
    border-radius: 12px;
}
body.dark .param-item { background: var(--bg-dark); }
.param-item label { grid-column: 1 / 2; grid-row: 1 / 2; font-weight: 500; }
.input-wrapper { grid-column: 1 / 2; grid-row: 2 / 3; display: flex; }
.status-badge { grid-column: 2 / 3; grid-row: 1 / 3; }
.param-input {
    width: 100%;
    border: none;
    background: transparent;
    font-size: 1.1rem;
    font-weight: 500;
    color: inherit;
    padding-left: 0;
}
.param-input:focus { outline: none; }
.input-unit { font-weight: 500; color: var(--text-muted-light); }
body.dark .input-unit { color: var(--text-muted-dark); }

.status-badge {
    font-size: 0.8rem;
    font-weight: 700;
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    text-align: center;
    min-width: 80px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
#statusAmmonia, #statusNitrite { color: var(--success); background-color: rgba(40, 167, 69, 0.15); }
#statusAmmonia.warn, #statusNitrite.warn { color: white; background-color: var(--danger); }
#statusNitrate.good { color: var(--success); background-color: rgba(40, 167, 69, 0.15); }
#statusNitrate.warn { color: #333; background-color: var(--warning); }
#statusGh, #statusKh { color: #17a2b8; background-color: rgba(23, 162, 184, 0.1); }

/* --- UNIT TOGGLE BUTTONS (GH/KH) --- */
.param-item.has-toggle {
    grid-template-rows: auto auto auto;
}

.param-item.has-toggle .status-badge {
    grid-row: 1 / 4;
}

.unit-toggle-group {
    display: flex;
    gap: 0.25rem;
    margin-top: 0.5rem;
    grid-column: 1 / 2;
    grid-row: 3 / 4;
}

.unit-toggle-btn {
    flex: 1;
    padding: 0.4rem 0.6rem;
    font-size: 0.75rem;
    font-weight: 600;
    border: 1px solid var(--card-border-light);
    border-radius: 6px;
    background: var(--bg-light);
    color: var(--text-muted-light);
    cursor: pointer;
    transition: all 0.2s ease;
}

body.dark .unit-toggle-btn {
    border-color: var(--card-border-dark);
    background: var(--bg-dark);
    color: var(--text-muted-dark);
}

.unit-toggle-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

body.dark .unit-toggle-btn:hover {
    color: var(--heading-dark);
}

.unit-toggle-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.unit-toggle-btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Subtle lift animation on param items when focused */
.param-item {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.param-item:focus-within {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.15);
}

.recommendations-container { padding: 1rem; }
.recommendations-container .section-header.mini { margin-bottom: 1rem; display: flex; align-items: center; }
.recommendations-container .section-header.mini h3 { font-size: 1.2rem; margin: 0; color: var(--heading-light); }
body.dark .recommendations-container .section-header.mini h3 { color: var(--heading-dark); }
.recommendations-box p { margin-bottom: 0.75rem; line-height: 1.5; }
.recommendations-box p:last-child { margin-bottom: 0; }
.recommendations-box strong { color: var(--primary); }
body.dark .recommendations-box strong { color: var(--primary-hover); }

/* --- CALCULATOR SECTION (RIGHT COLUMN) --- */
.calculator-grid { display: grid; gap: 1.5rem; }
.calculator-card { padding: 0; }
.dosing-card { padding: 0; }

.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
}
.step-number {
    background: var(--primary);
    color: white;
    font-weight: 700;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    flex-shrink: 0;
}
.card-header h3 { font-size: clamp(1.1rem, 2.5vw, 1.25rem); color: var(--heading-light); }
body.dark .card-header h3 { color: var(--heading-dark); }
.card-content { padding: 0 1.5rem 1.5rem; }

.input-row { display: flex; flex-wrap: wrap; gap: 1.5rem; }
.input-row > .input-group { flex: 1 1 180px; }
.input-group label { display: block; margin-bottom: 0.5rem; font-size: 0.9rem; font-weight: 500; color: var(--text-muted-light); }
body.dark .input-group label { color: var(--text-muted-dark); }
input[type=number].styled-input, .styled-select {
    width: 100%;
    padding: 0.85rem 1rem;
    border: 1px solid var(--card-border-light);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--bg-light);
    color: inherit;
    transition: all var(--transition-speed) ease;
}
body.dark input[type=number].styled-input, body.dark .styled-select {
    background: var(--bg-dark);
    border-color: var(--card-border-dark);
}
input.styled-input:focus, .styled-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

/* Dosing Card Specifics (Details/Summary) */
.dosing-summary {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    cursor: pointer;
    list-style: none;
}
.dosing-summary::-webkit-details-marker { display: none; }
.summary-content { flex-grow: 1; }
.summary-content h3 { font-size: clamp(1.1rem, 2.5vw, 1.25rem); margin: 0; color: var(--heading-light); }
body.dark .summary-content h3 { color: var(--heading-dark); }
.summary-icon { font-size: 1.5rem; transition: transform var(--transition-speed) ease; }
details[open] .summary-icon { transform: rotate(180deg); }
.details-content { padding: 0 1.5rem 1.5rem; }

.result-container { margin-top: 1.5rem; text-align: left; }
.result-display {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: var(--primary-light);
    padding: 1rem;
    border-radius: 10px;
}
body.dark .result-display { background: rgba(56, 139, 253, 0.15); }
.result { font-weight: 700; font-size: 1.2rem; color: var(--primary); flex-grow: 1; }
body.dark .result { color: #58a6ff; }
.split-info { font-size: 0.85rem; color: var(--text-muted-light); margin-top: 0.5rem; padding-left: 0.5rem; }
body.dark .split-info { color: var(--text-muted-dark); }
.copy-btn {
    background: transparent;
    border: 1px solid transparent;
    border-radius: 8px;
    padding: 0.5rem;
    font-size: 1.2rem;
    color: var(--primary);
    cursor: pointer;
    transition: all 0.2s;
}
.copy-btn:hover { background: rgba(255,255,255,0.5); border-color: var(--primary); }
body.dark .copy-btn { color: #58a6ff; }
body.dark .copy-btn:hover { background: rgba(0,0,0,0.2); }

#errors { margin-bottom: 1.5rem; color: var(--danger); font-size: 1rem; padding: 1rem; background: rgba(220, 53, 69, 0.1); border-left: 5px solid var(--danger); border-radius: 8px; display: none; }
#errors:not(:empty) { display: block; }

/* --- FOOTER & ACTIONS --- */
.main-footer {
    position: fixed;
    bottom: 0; left: 0; right: 0;
    background: var(--card-bg-light);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-top: 1px solid var(--card-border-light);
    box-shadow: 0 -4px 32px rgba(0,0,0,0.1);
    z-index: 100;
}
body.dark .main-footer {
    background: var(--card-bg-dark);
    border-top: 1px solid var(--card-border-dark);
}
.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem clamp(1rem, 5vw, 4rem);
    max-width: 1800px;
    margin: 0 auto;
}
.footer-info { font-size: 0.85rem; color: var(--text-muted-light); }
body.dark .footer-info { color: var(--text-muted-dark); }
/* (dead footer action styles removed in v6.1) */

/* --- MODAL --- */
.modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.7); backdrop-filter: blur(5px); z-index: 200; display: flex; align-items: center; justify-content: center; }
.modal-content {
    background: var(--bg-light);
    color: var(--text-light);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    max-width: 600px; width: 90%;
    position: relative;
    border: 1px solid var(--card-border-light);
    box-shadow: var(--shadow);
}
body.dark .modal-content {
    background: var(--bg-dark);
    color: var(--text-dark);
    border-color: var(--card-border-dark);
}
.modal-close-btn { position: absolute; top: 1rem; right: 1rem; background: none; border: none; font-size: 1.75rem; cursor: pointer; color: inherit; line-height: 1; }
.modal-header h2 { font-size: 1.5rem; border: none; }
.modal-body ul { list-style-position: inside; padding-left: 1rem; }
.modal-body li { margin-bottom: 0.75rem; }
.modal-body strong { color: var(--primary); }
body.dark .modal-body strong { color: #58a6ff; }

/* --- RESPONSIVE DESIGN --- */
@media (max-width: 1200px) {
    .main-grid {
        grid-template-columns: 1fr; /* Stack columns */
    }
}

@media (max-width: 768px) {
    body {
        padding-bottom: 0;
    }
    .main-header, .main-grid, .footer-content {
        padding-left: 1rem;
        padding-right: 1rem;
    }
    .logo-section { gap: 0.75rem; }
    .logo-icon { font-size: 2.5rem; }
    
    .footer-content {
        flex-direction: column;
        gap: 1rem;
        padding-top: 1rem;
        padding-bottom: 1rem;
    }
    .footer-actions {
        width: 100%;
        flex-direction: column;
        gap: 0.75rem;
    }
    .action-btn { justify-content: center; }

    .input-row { flex-direction: column; gap: 1rem; }

    /* Unit toggle responsive adjustments */
    .unit-toggle-btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.8rem;
    }
}

/* --- HAMBURGER MENU BUTTON --- */
.menu-btn {
    font-size: 1.5rem;
    padding: 0.5rem;
    border-radius: 8px;
    background: var(--card-bg-light);
    border: 1px solid var(--card-border-light);
}
body.dark .menu-btn {
    background: var(--card-bg-dark);
    border-color: var(--card-border-dark);
}
.menu-btn:hover {
    background: var(--primary-light);
}

/* --- HAMBURGER MENU OVERLAY --- */
.menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 150;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}
.menu-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* --- HAMBURGER MENU PANEL --- */
.menu-panel {
    position: fixed;
    top: 0;
    right: -320px;
    width: 320px;
    max-width: 90vw;
    height: 100%;
    background: var(--bg-light);
    border-left: 1px solid var(--card-border-light);
    box-shadow: -8px 0 32px rgba(0, 0, 0, 0.15);
    z-index: 200;
    transition: right 0.3s ease;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}
.menu-panel.active {
    right: 0;
}
body.dark .menu-panel {
    background: var(--bg-dark);
    border-color: var(--card-border-dark);
}

.menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--card-border-light);
}
body.dark .menu-header {
    border-color: var(--card-border-dark);
}
.menu-header h2 {
    font-size: 1.25rem;
    margin: 0;
    border: none;
    padding: 0;
}
.menu-close-btn {
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: inherit;
    line-height: 1;
    padding: 0;
}

.menu-body {
    flex: 1;
    padding: 1rem;
}

.menu-section {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--card-border-light);
}
body.dark .menu-section {
    border-color: var(--card-border-dark);
}
.menu-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
}
.menu-section h3 {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted-light);
    margin-bottom: 1rem;
}
body.dark .menu-section h3 {
    color: var(--text-muted-dark);
}

.menu-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
}

.menu-toggle-group {
    display: flex;
    gap: 0.25rem;
    background: var(--card-bg-light);
    border-radius: 8px;
    padding: 0.25rem;
}
body.dark .menu-toggle-group {
    background: var(--card-bg-dark);
}

.menu-toggle-btn {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    font-weight: 600;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: var(--text-muted-light);
    cursor: pointer;
    transition: all 0.2s ease;
}
body.dark .menu-toggle-btn {
    color: var(--text-muted-dark);
}
.menu-toggle-btn:hover {
    color: var(--primary);
}
.menu-toggle-btn.active {
    background: var(--primary);
    color: white;
}

.menu-hint {
    font-size: 0.85rem;
    color: var(--text-muted-light);
    margin-bottom: 0.75rem;
}
body.dark .menu-hint {
    color: var(--text-muted-dark);
}

.buffer-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.buffer-list li {
    margin-bottom: 0.5rem;
}
.menu-link {
    display: block;
    padding: 0.75rem 1rem;
    background: var(--card-bg-light);
    border-radius: 8px;
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
}
body.dark .menu-link {
    background: var(--card-bg-dark);
    color: var(--heading-dark);
}
.menu-link:hover {
    background: var(--primary-light);
    transform: translateX(4px);
}

.menu-actions {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.menu-action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.85rem 1rem;
    border: 1px solid var(--card-border-light);
    border-radius: 8px;
    background: var(--card-bg-light);
    color: inherit;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}
body.dark .menu-action-btn {
    background: var(--card-bg-dark);
    border-color: var(--card-border-dark);
}
.menu-action-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}
.menu-action-btn.danger {
    border-color: var(--danger);
    color: var(--danger);
}
.menu-action-btn.danger:hover {
    background: var(--danger);
    color: white;
}
.menu-action-btn.small {
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
}

.menu-version {
    font-size: 0.9rem;
    color: var(--text-muted-light);
    margin-bottom: 0.75rem;
}
body.dark .menu-version {
    color: var(--text-muted-dark);
}

/* --- STATIC FOOTER --- */
.main-footer.static {
    position: static;
    box-shadow: none;
    border-top: 1px solid var(--card-border-light);
    margin-top: 2rem;
}
body.dark .main-footer.static {
    border-color: var(--card-border-dark);
}
.main-footer.static .footer-content {
    justify-content: center;
    gap: 1rem;
}
.main-footer.static .footer-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}
.version-tag {
    background: var(--primary-light);
    color: var(--primary);
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
}
body.dark .version-tag {
    background: rgba(56, 139, 253, 0.15);
    color: var(--heading-dark);
}

/* (dead padding override removed in v6.1) */

/* --- VOLUME MODE TOGGLE --- */
.volume-mode-toggle {
    display: flex;
    gap: 0.25rem;
    background: var(--card-bg-light);
    border: 1px solid var(--card-border-light);
    border-radius: 8px;
    padding: 0.25rem;
    margin-bottom: 1rem;
}
body.dark .volume-mode-toggle {
    background: var(--card-bg-dark);
    border-color: var(--card-border-dark);
}

.vol-mode-btn {
    flex: 1;
    padding: 0.6rem 1rem;
    font-size: 0.9rem;
    font-weight: 600;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: var(--text-muted-light);
    cursor: pointer;
    transition: all 0.2s ease;
}
body.dark .vol-mode-btn {
    color: var(--text-muted-dark);
}
.vol-mode-btn:hover {
    color: var(--primary);
}
.vol-mode-btn.active {
    background: var(--primary);
    color: white;
}

/* --- DIMENSION UNIT TOGGLE --- */
.dim-unit-toggle {
    display: flex;
    gap: 0.25rem;
    margin-bottom: 1rem;
}

.dim-unit-btn {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid var(--card-border-light);
    border-radius: 6px;
    background: var(--bg-light);
    color: var(--text-muted-light);
    cursor: pointer;
    transition: all 0.2s ease;
}
body.dark .dim-unit-btn {
    background: var(--bg-dark);
    border-color: var(--card-border-dark);
    color: var(--text-muted-dark);
}
.dim-unit-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}
.dim-unit-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.calculated-volume {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    background: var(--primary-light);
    border-radius: 8px;
    font-size: 0.95rem;
}
body.dark .calculated-volume {
    background: rgba(56, 139, 253, 0.15);
}
.calculated-volume strong {
    font-size: 1.1rem;
    color: var(--primary);
}
body.dark .calculated-volume strong {
    color: var(--heading-dark);
}

/* --- HIDDEN SECTIONS (Advanced Buffers) --- */
.hidden-section {
    display: none !important;
}

.hidden-section.visible {
    display: block !important;
}

/* --- SECTION DIVIDER --- */
.advanced-buffers-section {
    margin: 1rem 0;
}
.section-divider {
    display: flex;
    align-items: center;
    gap: 1rem;
}
.section-divider::before,
.section-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--card-border-light);
}
body.dark .section-divider::before,
body.dark .section-divider::after {
    background: var(--card-border-dark);
}
.section-divider span {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted-light);
    white-space: nowrap;
}
body.dark .section-divider span {
    color: var(--text-muted-dark);
}

/* --- PRODUCT INFO TEXT --- */
.product-info {
    font-size: 0.9rem;
    color: var(--text-muted-light);
    margin-bottom: 1rem;
    line-height: 1.5;
}
body.dark .product-info {
    color: var(--text-muted-dark);
}

/* --- NITRATE ESTIMATE --- */
.nitrate-estimate {
    margin-top: 0.5rem;
    padding: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted-light);
    background: rgba(40, 167, 69, 0.1);
    border-radius: 6px;
}
body.dark .nitrate-estimate {
    color: var(--text-muted-dark);
    background: rgba(40, 167, 69, 0.15);
}

/* --- CHANGELOG LIST --- */
.changelog-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.changelog-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--card-border-light);
}
body.dark .changelog-list li {
    border-color: var(--card-border-dark);
}
.changelog-list li:last-child {
    border-bottom: none;
}
.changelog-list strong {
    display: inline-block;
    min-width: 80px;
    color: var(--primary);
}
body.dark .changelog-list strong {
    color: var(--heading-dark);
}

/* --- RESPONSIVE UPDATES FOR NEW ELEMENTS --- */
@media (max-width: 768px) {
    .menu-panel {
        width: 100%;
        max-width: 100%;
        right: -100%;
    }

    .volume-mode-toggle {
        flex-direction: column;
    }

    .dim-unit-toggle {
        justify-content: center;
    }

    .main-footer.static .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .menu-header {
        padding: 1rem;
    }

    .menu-body {
        padding: 0.75rem;
    }

    .header-controls {
        gap: 0.5rem;
    }

    .menu-btn {
        padding: 0.4rem;
    }
}

/* --- v6.0: PROFILE TABS --- */
.profile-tabs {
    display: flex;
    gap: 0.5rem;
    padding: 0.75rem clamp(1rem, 5vw, 4rem);
    max-width: 1800px;
    margin: 0 auto;
    justify-content: center;
}

.profile-tab {
    padding: 0.65rem 1.25rem;
    border: 1px solid var(--card-border-light);
    border-radius: 8px;
    background: var(--card-bg-light);
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

body.dark .profile-tab {
    background: var(--card-bg-dark);
    border-color: var(--card-border-dark);
    color: var(--text-dark);
}

.profile-tab:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.profile-tab.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.profile-tab:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* --- v6.0: SCALE DROPDOWN (unit selector on dynamic cards) --- */
select.scale-select {
    padding: 0.7rem 0.75rem;
    font-size: 0.85rem;
    border: 1px solid var(--card-border-light);
    border-radius: 8px;
    background: var(--bg-light);
    color: var(--text-light);
    cursor: pointer;
    transition: all 0.2s ease;
    width: 100%;
}

body.dark select.scale-select {
    background: var(--bg-dark);
    border-color: var(--card-border-dark);
    color: var(--text-dark);
}

select.scale-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

/* --- v6.0: SALTWATER PARAM BADGES --- */
#statusSalinity, #statusAlkalinity, #statusCalcium, #statusMagnesium, #statusDo {
    color: #17a2b8;
    background-color: rgba(23, 162, 184, 0.1);
}
#statusSalinity.good, #statusAlkalinity.good, #statusCalcium.good, #statusMagnesium.good, #statusDo.good {
    color: var(--success);
    background-color: rgba(40, 167, 69, 0.15);
}
#statusSalinity.warn, #statusAlkalinity.warn, #statusCalcium.warn, #statusMagnesium.warn, #statusDo.warn {
    color: white;
    background-color: var(--danger);
}

#statusPh {
    color: var(--text-muted-light);
    background-color: rgba(108, 117, 125, 0.1);
}
body.dark #statusPh {
    color: var(--text-muted-dark);
}

/* --- v6.0: SUBSTRATE UNIT TOGGLE WRAPPER --- */
.sub-unit-toggle {
    display: flex;
    gap: 0.25rem;
    margin-bottom: 1rem;
}

/* --- v6.0: SUBSTRATE UNIT TOGGLE BUTTONS --- */
.sub-unit-btn {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid var(--card-border-light);
    border-radius: 6px;
    background: var(--bg-light);
    color: var(--text-muted-light);
    cursor: pointer;
    transition: all 0.2s ease;
}

body.dark .sub-unit-btn {
    background: var(--bg-dark);
    border-color: var(--card-border-dark);
    color: var(--text-muted-dark);
}

.sub-unit-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.sub-unit-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* --- v6.0: DYNAMIC CALCULATORS GRID --- */
#dynamicCalculators {
    display: grid;
    gap: 1.5rem;
}

#dynamicCalculators .dosing-card {
    margin-bottom: 0; /* grid gap handles spacing */
}

/* Scale-select sits flush next to the number input */
#dynamicCalculators .input-wrapper {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 0.5rem;
}
#dynamicCalculators .input-wrapper .styled-input {
    width: 100%;
    min-width: 0;
}
#dynamicCalculators .input-wrapper .scale-select {
    width: auto;
    min-width: 5.5rem;
    max-width: 7rem;
}

/* --- v6.0: RESPONSIVE --- */
@media (max-width: 768px) {
    .profile-tabs {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.4rem;
        padding: 0.6rem 1rem;
    }

    .profile-tab {
        padding: 0.55rem 1rem;
        font-size: 0.88rem;
    }

    select.scale-select {
        font-size: 0.82rem;
    }
}

@media (max-width: 480px) {
    .profile-tab {
        padding: 0.5rem 0.8rem;
        font-size: 0.82rem;
    }
}

/* --- v6.1: RECOMMENDATION STYLES --- */
.reco-item {
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    border-left: 4px solid transparent;
    line-height: 1.6;
    font-size: 0.9rem;
}
.reco-item.reco-ok {
    border-left-color: var(--success);
    background: rgba(40, 167, 69, 0.08);
}
.reco-item.reco-critical {
    border-left-color: var(--danger);
    background: rgba(220, 53, 69, 0.08);
}
.reco-item.reco-warning {
    border-left-color: #ff9800;
    background: rgba(255, 152, 0, 0.08);
}
.reco-item.reco-caution {
    border-left-color: var(--warning);
    background: rgba(255, 193, 7, 0.06);
}
.reco-item.reco-info {
    border-left-color: var(--primary);
    background: rgba(0, 123, 255, 0.06);
}
.reco-icon {
    margin-right: 0.5rem;
    font-size: 1.1rem;
}
.reco-badge {
    display: inline-block;
    font-size: 0.65rem;
    font-weight: 700;
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-right: 0.5rem;
    vertical-align: middle;
}
.reco-badge.reco-critical { background: var(--danger); color: white; }
.reco-badge.reco-warning { background: #ff9800; color: white; }
.reco-badge.reco-caution { background: var(--warning); color: #333; }
.reco-badge.reco-info { background: var(--primary-light); color: var(--primary); }
body.dark .reco-badge.reco-info { background: rgba(56, 139, 253, 0.2); color: #58a6ff; }

.reco-range {
    font-size: 0.8rem;
    color: var(--text-muted-light);
    margin-left: 0.25rem;
}
body.dark .reco-range { color: var(--text-muted-dark); }

.reco-action {
    font-size: 0.85rem;
    color: var(--text-muted-light);
    padding-left: 2rem;
}
body.dark .reco-action { color: var(--text-muted-dark); }
.reco-action strong { color: var(--primary); }
body.dark .reco-action strong { color: #58a6ff; }

.reco-emergency {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--danger);
    padding-left: 2rem;
}

/* --- v6.1: REAL-TIME BEACON --- */
.realtime-beacon {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.3rem 0.7rem;
    border-radius: 14px;
    border: 1px solid rgba(40, 167, 69, 0.14);
    background: rgba(40, 167, 69, 0.1);
    color: var(--success);
    user-select: none;
    box-shadow: 0 8px 18px rgba(40, 167, 69, 0.08);
}
body.dark .realtime-beacon {
    border-color: rgba(63, 185, 80, 0.18);
    background: rgba(40, 167, 69, 0.15);
    color: #3fb950;
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.2);
}
.section-header .realtime-beacon {
    margin-left: auto;
}
.header-status-beacon {
    margin-top: 0.55rem;
    width: fit-content;
}
.beacon-copy {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.05rem;
    line-height: 1.05;
}
.beacon-label {
    font-size: 0.62rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}
.beacon-status {
    font-size: 0.56rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    color: var(--text-muted-light);
}
body.dark .beacon-status {
    color: var(--text-muted-dark);
}
.beacon-dot {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    animation: beaconPulse 2s ease-in-out infinite;
    box-shadow: 0 0 4px var(--success);
}
body.dark .beacon-dot {
    background: #3fb950;
    box-shadow: 0 0 6px #3fb950;
}
@keyframes beaconPulse {
    0%, 100% { opacity: 1; transform: scale(1); box-shadow: 0 0 4px var(--success); }
    50% { opacity: 0.4; transform: scale(0.75); box-shadow: 0 0 8px var(--success); }
}
.realtime-beacon.has-critical .beacon-dot {
    background: var(--danger);
    box-shadow: 0 0 6px var(--danger);
    animation: beaconPulseUrgent 0.8s ease-in-out infinite;
}
.realtime-beacon.has-critical {
    background: rgba(220, 53, 69, 0.1);
    border-color: rgba(220, 53, 69, 0.18);
    color: var(--danger);
}
.realtime-beacon.has-critical .beacon-label,
.realtime-beacon.has-critical .beacon-status { color: var(--danger); }
body.dark .realtime-beacon.has-critical {
    background: rgba(220, 53, 69, 0.15);
    border-color: rgba(248, 81, 73, 0.2);
    color: #f85149;
}
body.dark .realtime-beacon.has-critical .beacon-dot {
    background: #f85149;
    box-shadow: 0 0 8px #f85149;
}
body.dark .realtime-beacon.has-critical .beacon-label,
body.dark .realtime-beacon.has-critical .beacon-status { color: #f85149; }
@keyframes beaconPulseUrgent {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.3; transform: scale(0.6); }
}

/* --- v6.1: EMERGENCY LOADER --- */
.emergency-loader {
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    background: rgba(220, 53, 69, 0.06);
    border-left: 4px solid var(--danger);
    overflow: hidden;
    position: relative;
}
body.dark .emergency-loader {
    background: rgba(220, 53, 69, 0.1);
}
.loader-bar {
    position: absolute;
    top: 0;
    left: 0;
    height: 3px;
    width: 0;
    background: linear-gradient(90deg, var(--danger), #ff6b6b, var(--danger));
    animation: loaderScan 1.2s ease-in-out forwards;
    border-radius: 0 2px 2px 0;
}
@keyframes loaderScan {
    0% { width: 0; }
    60% { width: 85%; }
    100% { width: 100%; }
}
.loader-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--danger);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.loader-text::before {
    content: '';
    display: inline-block;
    width: 12px;
    height: 12px;
    border: 2px solid var(--danger);
    border-top-color: transparent;
    border-radius: 50%;
    animation: loaderSpin 0.6s linear infinite;
}
@keyframes loaderSpin {
    to { transform: rotate(360deg); }
}

/* Critical flash on reco container when critical issues found */
.recommendations-container.critical-flash {
    animation: criticalFlash 0.4s ease-out 1;
}
@keyframes criticalFlash {
    0% { box-shadow: 0 0 0 0 rgba(220, 53, 69, 0.4); }
    50% { box-shadow: 0 0 20px 4px rgba(220, 53, 69, 0.2); }
    100% { box-shadow: none; }
}

/* --- v6.1: CO2 ESTIMATE --- */
.co2-estimate {
    padding: 0.6rem 1rem;
    margin-bottom: 0.75rem;
    background: rgba(40, 167, 69, 0.1);
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--success);
}
body.dark .co2-estimate {
    background: rgba(40, 167, 69, 0.15);
    color: #3fb950;
}

/* --- v6.1: PARAMETER HISTORY --- */
.param-history-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--card-border-light);
}
body.dark .param-history-actions {
    border-top-color: var(--card-border-dark);
}
.history-btn {
    flex: 1;
    padding: 0.6rem 1rem;
    border: 1px solid var(--primary);
    border-radius: 8px;
    background: var(--primary);
    color: white;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}
.history-btn:hover {
    background: var(--primary-hover);
}
.history-btn.secondary {
    background: transparent;
    color: var(--primary);
}
.history-btn.secondary:hover {
    background: var(--primary-light);
}
body.dark .history-btn.secondary {
    color: #58a6ff;
    border-color: rgba(56, 139, 253, 0.4);
}

.history-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}
.history-table th,
.history-table td {
    padding: 0.5rem 0.6rem;
    text-align: center;
    border-bottom: 1px solid var(--card-border-light);
}
body.dark .history-table th,
body.dark .history-table td {
    border-bottom-color: var(--card-border-dark);
}
.history-table th {
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-muted-light);
}
body.dark .history-table th {
    color: var(--text-muted-dark);
}
.history-note {
    font-size: 0.8rem;
    color: var(--text-muted-light);
    margin-top: 0.5rem;
    text-align: center;
}
body.dark .history-note { color: var(--text-muted-dark); }

.modal-wide {
    max-width: 800px;
}

/* --- v6.1: FOCUS-VISIBLE for toggle buttons --- */
.vol-mode-btn:focus-visible,
.dim-unit-btn:focus-visible,
.sub-unit-btn:focus-visible,
.menu-toggle-btn:focus-visible,
.history-btn:focus-visible,
.menu-action-btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}