/* Custom Styling & Utilities for IELTS Master - Authentic CD IELTS & Modern Luxury UI */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800;900&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;0,6..72,700;1,6..72,400&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
    --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-serif: 'Newsreader', Georgia, Cambria, "Times New Roman", serif;
    --font-mono: 'JetBrains Mono', Menlo, Monaco, Consolas, monospace;

    /* Official Cambridge / British Council Brand Signature */
    --ielts-red: #D91C29;
    --ielts-red-dark: #B5121F;
    --ielts-red-light: #FEE2E2;
    --ielts-navy: #0F172A;
    --ielts-navy-surface: #1E293B;
    --ielts-paper: #FCFAF7;

    --brand-50: #EEF2FF;
    --brand-100: #E0E7FF;
    --brand-500: #6366F1;
    --brand-600: #4F46E5;
    --brand-700: #4338CA;
    --brand-900: #312E81;
}

body {
    font-family: var(--font-sans);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    background-color: #F8FAFC;
    color: #0F172A;
}

.font-sans { font-family: var(--font-sans) !important; }
.font-serif { font-family: var(--font-serif) !important; }
.font-mono { font-family: var(--font-mono) !important; }

/* Authentic IELTS Brand Red */
.bg-ielts-red { background-color: var(--ielts-red); }
.text-ielts-red { color: var(--ielts-red); }
.border-ielts-red { border-color: var(--ielts-red); }

/* Luxury Elevated Cards */
.card-lift {
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.25s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.2s ease;
}
.card-lift:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 30px -10px rgba(15, 23, 42, 0.08), 0 4px 12px -4px rgba(15, 23, 42, 0.04);
}

.card-interactive {
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}
.card-interactive:hover {
    transform: translateY(-3px) scale(1.005);
    box-shadow: 0 18px 36px -10px rgba(15, 23, 42, 0.12);
}

/* Glassmorphism accents */
.glass-panel {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

.glass-dark {
    background: rgba(15, 23, 42, 0.94);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}

/* Subtle Shimmer & Glow */
.glow-indigo {
    box-shadow: 0 0 25px -5px rgba(99, 102, 241, 0.35);
}
.glow-emerald {
    box-shadow: 0 0 25px -5px rgba(16, 185, 129, 0.35);
}
.glow-amber {
    box-shadow: 0 0 25px -5px rgba(245, 158, 11, 0.35);
}
.glow-red {
    box-shadow: 0 0 25px -5px rgba(217, 28, 41, 0.35);
}

/* Custom Scrollbars */
.custom-scrollbar::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
.custom-scrollbar::-webkit-scrollbar-track {
    background: rgba(241, 245, 249, 0.7);
    border-radius: 9999px;
}
.custom-scrollbar::-webkit-scrollbar-thumb {
    background: #CBD5E1;
    border-radius: 9999px;
}
.custom-scrollbar::-webkit-scrollbar-thumb:hover {
    background: #94A3B8;
}

/* ==========================================================================
   OFFICIAL COMPUTER-DELIVERED IELTS (CD IELTS) SIGNATURE STYLING
   ========================================================================== */

/* Authentic CD IELTS Examination Header Strip */
.cd-ielts-exam-header {
    background: #0F172A;
    color: #FFFFFF;
    border-bottom: 2px solid #E2E8F0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

/* Authentic CD IELTS Parchment Reading Paper */
.cd-ielts-paper {
    background-color: #FAF8F5;
    border: 1px solid #E2E8F0;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.02);
}

/* Official Paragraph Letter Badge: [ Paragraph A ] */
.cd-paragraph-marker {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-family: var(--font-sans);
    font-weight: 800;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    padding: 2px 8px;
    background: #E2E8F0;
    color: #1E293B;
    border-radius: 4px;
    margin-bottom: 8px;
    border: 1px solid #CBD5E1;
}

/* Official CD IELTS Bottom Question Palette Bar */
.cd-ielts-bottom-bar {
    background: #FFFFFF;
    border-top: 2px solid #CBD5E1;
    box-shadow: 0 -4px 16px rgba(15, 23, 42, 0.06);
}

/* Official CD IELTS Square Question Palette Button */
.cd-palette-btn {
    width: 32px;
    height: 32px;
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 700;
    border-radius: 4px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    position: relative;
    transition: all 0.15s ease-in-out;
    border: 1px solid #94A3B8;
    background: #FFFFFF;
    color: #1E293B;
    user-select: none;
}
.cd-palette-btn:hover {
    background: #F1F5F9;
    border-color: #475569;
}
/* Unanswered question: clean white with border */
.cd-palette-btn.unanswered {
    background: #FFFFFF;
    border: 1px solid #94A3B8;
    color: #334155;
}
/* Answered question: solid fill with indicator */
.cd-palette-btn.answered {
    background: #0F172A;
    border-color: #0F172A;
    color: #FFFFFF;
}
/* Currently selected active question */
.cd-palette-btn.active-q {
    outline: 2px solid #2563EB;
    outline-offset: 1px;
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.3);
}
/* Flagged for Review: Dog-ear triangle or badge */
.cd-palette-btn.flagged::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 0 8px 8px 0;
    border-color: transparent #F59E0B transparent transparent;
}
/* Graded Correct / Incorrect states */
.cd-palette-btn.graded-correct {
    background: #10B981 !important;
    border-color: #059669 !important;
    color: #FFFFFF !important;
}
.cd-palette-btn.graded-incorrect {
    background: #EF4444 !important;
    border-color: #DC2626 !important;
    color: #FFFFFF !important;
}

/* Reading Split Pane Responsiveness */
@media (min-width: 1024px) {
    .split-pane-container {
        height: calc(100vh - 165px);
        min-height: 640px;
    }
}
@media (max-width: 1023px) {
    .split-pane-container {
        height: auto;
        min-height: auto;
    }
}

/* Reading Font Size Variations */
.reading-text-sm {
    font-size: 0.9375rem !important;
    line-height: 1.8 !important;
}
.reading-text-base {
    font-size: 1.0625rem !important;
    line-height: 1.85 !important;
}
.reading-text-lg {
    font-size: 1.25rem !important;
    line-height: 1.95 !important;
}

/* Text Highlighting in Reading */
.highlighted {
    background-color: #FEF08A !important;
    border-radius: 3px;
    padding: 1px 3px;
    box-shadow: 0 0 0 1px #FDE047;
}

/* Audio Waveform animation */
@keyframes soundwave {
    0%, 100% { height: 4px; }
    50% { height: 22px; }
}

.soundwave-bar {
    width: 3px;
    background: linear-gradient(180deg, #818CF8 0%, #4F46E5 100%);
    border-radius: 9999px;
    animation: soundwave 1.2s ease-in-out infinite;
}
.soundwave-bar:nth-child(2) { animation-delay: 0.15s; }
.soundwave-bar:nth-child(3) { animation-delay: 0.3s; }
.soundwave-bar:nth-child(4) { animation-delay: 0.45s; }
.soundwave-bar:nth-child(5) { animation-delay: 0.6s; }

/* Pulse animation for active voice recording */
@keyframes pulse-ring {
    0% { transform: scale(0.96); box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.6); }
    70% { transform: scale(1.02); box-shadow: 0 0 0 10px rgba(239, 68, 68, 0); }
    100% { transform: scale(0.96); box-shadow: 0 0 0 0 rgba(239, 68, 68, 0); }
}

.recording-pulse {
    animation: pulse-ring 1.5s infinite;
}

/* Nav Tab Active Indicators */
.nav-tab {
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}
.nav-tab.active {
    background: #0F172A;
    color: #FFFFFF;
    font-weight: 700;
    box-shadow: 0 4px 12px rgba(15, 23, 42, 0.15);
}
.nav-tab.active svg {
    color: #F8FAFC !important;
}

/* Mobile Drawer Transitions */
#mobile-drawer {
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.3s ease;
}
#mobile-drawer.drawer-open {
    transform: translateX(0);
    visibility: visible;
}
#mobile-drawer.drawer-closed {
    transform: translateX(-100%);
    visibility: hidden;
}

#mobile-backdrop {
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
#mobile-backdrop.backdrop-open {
    opacity: 1;
    visibility: visible;
}
#mobile-backdrop.backdrop-closed {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

/* Animated gradient background accent */
.hero-gradient {
    background: radial-gradient(circle at 10% 10%, rgba(217, 28, 41, 0.04) 0%, transparent 35%),
                radial-gradient(circle at 90% 15%, rgba(37, 99, 235, 0.05) 0%, transparent 40%),
                radial-gradient(circle at 50% 90%, rgba(99, 102, 241, 0.04) 0%, transparent 45%),
                #F8FAFC;
}

/* Modern Dark Mode Styling */
body.dark-mode, body.cd-theme-dark {
    background-color: #0B0F17 !important;
    background-image: none !important;
    color: #F1F5F9 !important;
}

body.dark-mode .bg-white,
body.cd-theme-dark .bg-white {
    background-color: #111827 !important;
    color: #F1F5F9 !important;
    border-color: #1F2937 !important;
}

body.dark-mode aside,
body.cd-theme-dark aside,
body.dark-mode header,
body.cd-theme-dark header {
    background-color: #111827 !important;
    color: #F1F5F9 !important;
    border-color: #1F2937 !important;
}

body.dark-mode .cd-ielts-paper,
body.cd-theme-dark .cd-ielts-paper {
    background-color: #111827 !important;
    color: #E2E8F0 !important;
    border-color: #1F2937 !important;
}

body.dark-mode .bg-slate-50,
body.dark-mode .bg-slate-100,
body.cd-theme-dark .bg-slate-50,
body.cd-theme-dark .bg-slate-100 {
    background-color: #1E293B !important;
    color: #CBD5E1 !important;
    border-color: #334155 !important;
}

body.dark-mode .text-slate-800,
body.dark-mode .text-slate-900,
body.dark-mode .text-slate-700,
body.cd-theme-dark .text-slate-800,
body.cd-theme-dark .text-slate-900,
body.cd-theme-dark .text-slate-700 {
    color: #F8FAFC !important;
}

body.dark-mode .text-slate-500,
body.dark-mode .text-slate-600,
body.cd-theme-dark .text-slate-500,
body.cd-theme-dark .text-slate-600 {
    color: #94A3B8 !important;
}

body.dark-mode .border-slate-200,
body.dark-mode .border-slate-100,
body.cd-theme-dark .border-slate-200,
body.cd-theme-dark .border-slate-100 {
    border-color: #1F2937 !important;
}

body.dark-mode input,
body.dark-mode textarea,
body.dark-mode select,
body.cd-theme-dark input,
body.cd-theme-dark textarea,
body.cd-theme-dark select {
    background-color: #0F172A !important;
    color: #F8FAFC !important;
    border-color: #334155 !important;
}

body.dark-mode .hero-gradient,
body.cd-theme-dark .hero-gradient {
    background: #0B0F17 !important;
}


/* Elegant Radio & Checkbox buttons */
input[type="radio"]:checked, input[type="checkbox"]:checked {
    accent-color: var(--ielts-red);
}