/* ========================================
   ConfTracker - Tech Event Design System
   Modern • Airy • Card-Based
   ======================================== */

/* Geist Font Import */
@import url('https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=Geist+Mono:wght@400;500;600&display=swap');

/* ========================================
   CSS Custom Properties
   ======================================== */
:root {
    /* Base Colors */
    --color-bg: #FAFAFA;
    --color-bg-elevated: #FFFFFF;
    --color-bg-subtle: #F4F4F5;
    --color-bg-muted: #E4E4E7;

    /* Text Colors */
    --color-text: #18181B;
    --color-text-secondary: #52525B;
    --color-text-muted: #A1A1AA;
    --color-text-inverse: #FFFFFF;

    /* Accent Colors - Vibrant Tech Palette */
    --color-primary: #6366F1;         /* Indigo */
    --color-primary-hover: #4F46E5;
    --color-primary-subtle: #EEF2FF;

    /* Deadline Status Colors */
    --color-urgent: #EF4444;          /* Red */
    --color-urgent-bg: #FEF2F2;
    --color-urgent-border: #FECACA;

    --color-soon: #F59E0B;            /* Amber */
    --color-soon-bg: #FFFBEB;
    --color-soon-border: #FDE68A;

    --color-open: #10B981;            /* Emerald */
    --color-open-bg: #ECFDF5;
    --color-open-border: #A7F3D0;

    --color-expired: #9CA3AF;         /* Gray */
    --color-expired-bg: #F9FAFB;

    /* Category Colors */
    --color-cat-ml: #8B5CF6;          /* Purple */
    --color-cat-nlp: #06B6D4;         /* Cyan */
    --color-cat-cv: #EC4899;          /* Pink */
    --color-cat-ai: #6366F1;          /* Indigo */
    --color-cat-other: #64748B;       /* Slate */

    /* Saved Color */
    --color-saved: hsl(340, 82%, 52%);
    --color-saved-bg: hsl(340, 100%, 97%);
    --color-saved-border: hsl(340, 82%, 80%);

    /* Typography */
    --font-sans: 'Geist', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'Geist Mono', 'SF Mono', Consolas, monospace;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;

    /* Sizing */
    --max-width: 1280px;
    --nav-height: 64px;

    /* Borders */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    --border-color: #E4E4E7;
    --border: 1px solid var(--border-color);

    /* Shadows */
    --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -1px rgba(0,0,0,0.04);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.08), 0 10px 10px -5px rgba(0,0,0,0.03);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.15);

    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
    --duration-fast: 150ms;
    --duration-base: 200ms;
    --duration-slow: 300ms;
}

/* Dark Theme */
[data-theme="dark"] {
    --color-bg: #0a0a0c;
    --color-bg-elevated: #121216;
    --color-bg-subtle: #1a1a1f;
    --color-bg-muted: #2a2a32;

    --color-text: #e8e8ec;
    --color-text-secondary: #9090a0;
    --color-text-muted: #606070;
    --color-text-inverse: #0a0a0c;

    --color-primary: #7c6aff;
    --color-primary-hover: #9486ff;
    --color-primary-subtle: rgba(124, 106, 255, 0.15);

    --color-urgent-bg: rgba(255, 77, 106, 0.12);
    --color-urgent-border: rgba(255, 77, 106, 0.3);
    --color-soon-bg: rgba(255, 184, 77, 0.12);
    --color-soon-border: rgba(245, 158, 11, 0.3);
    --color-open-bg: rgba(77, 255, 136, 0.12);
    --color-open-border: rgba(16, 185, 129, 0.3);
    --color-expired-bg: rgba(96, 96, 112, 0.12);

    --border-color: #2a2a32;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(124, 106, 255, 0.3);

    --color-saved-bg: rgba(255, 126, 179, 0.1);
    --color-saved-border: rgba(255, 126, 179, 0.4);
}

/* ========================================
   Reset & Base
   ======================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
    min-height: 100vh;
}

/* Subtle grid background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    background-image:
        linear-gradient(to right, var(--border-color) 1px, transparent 1px),
        linear-gradient(to bottom, var(--border-color) 1px, transparent 1px);
    background-size: 80px 80px;
    opacity: 0.4;
    mask-image: radial-gradient(ellipse 80% 50% at 50% 0%, black 40%, transparent 100%);
    -webkit-mask-image: radial-gradient(ellipse 80% 50% at 50% 0%, black 40%, transparent 100%);
}

[data-theme="dark"] body::before {
    opacity: 0.15;
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
}

/* ========================================
   Layout
   ======================================== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* ========================================
   Navigation - Modern Header
   ======================================== */
.header {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    height: var(--nav-height);
}

[data-theme="dark"] .header {
    background: rgba(10, 10, 12, 0.8);
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.header__brand {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    transition: opacity var(--duration-fast);
}

.header__brand:hover {
    opacity: 0.7;
}

.header__logo {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
}

.header__title h1 {
    font-size: 18px;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--color-text);
}

.header__subtitle {
    display: none;
}

.header__stats {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.stat {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 14px;
    color: var(--color-text-secondary);
}

.stat__value {
    font-family: var(--font-mono);
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text);
}

.stat--accent .stat__value {
    color: var(--color-primary);
}

.stat__label {
    font-size: 13px;
    color: var(--color-text-muted);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-12);
    align-items: center;
    padding: var(--space-12) var(--space-6) var(--space-10);
    min-height: 400px;
    max-width: var(--max-width);
    margin: 0 auto;
}

@media (max-width: 900px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero__visual {
        display: none;
    }
}

.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    font-size: 13px;
    font-weight: 600;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-full);
    margin-bottom: var(--space-5);
}

.hero__title {
    font-size: clamp(32px, 5vw, 52px);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: var(--color-text);
    margin-bottom: var(--space-5);
}

.hero__title-gradient {
    display: block;
    background: linear-gradient(135deg, var(--color-primary) 0%, #EC4899 50%, #F59E0B 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero__subtitle {
    font-size: 18px;
    line-height: 1.6;
    color: var(--color-text-secondary);
    max-width: 500px;
    margin-bottom: var(--space-8);
}

@media (max-width: 900px) {
    .hero__subtitle {
        margin-left: auto;
        margin-right: auto;
    }
}

.hero__stats {
    display: flex;
    gap: var(--space-8);
}

@media (max-width: 900px) {
    .hero__stats {
        justify-content: center;
    }
}

.hero__stat {
    text-align: left;
}

@media (max-width: 900px) {
    .hero__stat {
        text-align: center;
    }
}

.hero__stat-value {
    display: block;
    font-size: 32px;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.hero__stat-label {
    font-size: 13px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Hero Visual */
.hero__visual {
    position: relative;
    height: 350px;
}

.hero__circles {
    position: absolute;
    inset: 0;
}

.hero__circle {
    position: absolute;
    border-radius: 50%;
    opacity: 0.6;
}

.hero__circle--1 {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.3) 0%, rgba(236, 72, 153, 0.2) 100%);
    top: 0;
    right: 0;
    animation: float 8s ease-in-out infinite;
}

.hero__circle--2 {
    width: 200px;
    height: 200px;
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.3) 0%, rgba(6, 182, 212, 0.2) 100%);
    bottom: 20px;
    right: 100px;
    animation: float 6s ease-in-out infinite reverse;
}

.hero__circle--3 {
    width: 150px;
    height: 150px;
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.3) 0%, rgba(239, 68, 68, 0.2) 100%);
    top: 50px;
    right: 200px;
    animation: float 7s ease-in-out infinite 1s;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.hero__icons {
    position: absolute;
    inset: 0;
}

.hero__icon {
    position: absolute;
    font-size: 40px;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.1));
    animation: bounce 3s ease-in-out infinite;
}

.hero__icon--1 { top: 30px; right: 80px; animation-delay: 0s; }
.hero__icon--2 { top: 100px; right: 220px; animation-delay: 0.5s; }
.hero__icon--3 { bottom: 100px; right: 50px; animation-delay: 1s; }
.hero__icon--4 { bottom: 50px; right: 200px; animation-delay: 1.5s; }
.hero__icon--5 { top: 180px; right: 30px; animation-delay: 2s; }

@keyframes bounce {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-10px) rotate(5deg); }
}

/* ========================================
   Filter Bar - Modern Controls
   ======================================== */
.filters {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-6);
    padding: var(--space-4) var(--space-5);
    background: var(--color-bg-elevated);
    border: var(--border);
    border-radius: var(--radius-lg);
    max-width: var(--max-width);
    margin-left: auto;
    margin-right: auto;
}

.filters__main {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.filters__toggles {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.filters__divider {
    width: 1px;
    height: 20px;
    background: var(--border-color);
}

/* Filter Group */
.filter-group {
    position: relative;
}

.filter-toggle {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-family: var(--font-sans);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
    background: var(--color-bg-subtle);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    padding: var(--space-2) var(--space-3);
    cursor: pointer;
    transition: all var(--duration-fast);
}

.filter-toggle:hover {
    background: var(--color-bg-muted);
}

.filter-toggle.active {
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.filter-toggle__icon {
    display: flex;
    opacity: 0.7;
}

.filter-toggle__text {
    font-weight: 500;
}

.filter-toggle__count {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 20px;
    font-size: 11px;
    font-weight: 600;
    color: white;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    padding: 0 var(--space-1);
    opacity: 0;
    transform: scale(0.8);
    transition: all var(--duration-fast);
}

.filter-toggle__count.visible {
    opacity: 1;
    transform: scale(1);
}

/* Dropdown */
.dropdown {
    position: absolute;
    top: calc(100% + var(--space-2));
    left: 0;
    z-index: 50;
    min-width: 320px;
    max-width: 500px;
    max-height: 400px;
    overflow-y: auto;
    background: var(--color-bg-elevated);
    border: var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    box-shadow: var(--shadow-xl);
    animation: dropdownShow 0.15s var(--ease-out);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all var(--duration-base);
}

.dropdown.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

@keyframes dropdownShow {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.dropdown__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: var(--space-3);
    margin-bottom: var(--space-3);
    border-bottom: var(--border);
    font-size: 13px;
    color: var(--color-text-secondary);
}

.dropdown__clear {
    font-size: 12px;
    color: var(--color-primary);
    background: none;
    border: none;
    cursor: pointer;
    transition: color var(--duration-fast);
}

.dropdown__clear:hover {
    color: var(--color-primary-hover);
}

.dropdown__content {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

/* Topic Chips */
.topic-chip {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    font-size: 12px;
    font-weight: 500;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--duration-fast);
    border: 1px solid var(--border-color);
    background: var(--color-bg-elevated);
    color: var(--color-text-secondary);
}

.topic-chip:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.topic-chip.selected {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
    box-shadow: 0 2px 4px rgba(99, 102, 241, 0.3);
}

/* Filter Select */
.filter-select {
    appearance: none;
    font-family: var(--font-sans);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
    background: var(--color-bg-subtle);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    padding: var(--space-2) var(--space-10) var(--space-2) var(--space-3);
    cursor: pointer;
    transition: all var(--duration-fast);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2371717A' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right var(--space-3) center;
}

.filter-select:hover {
    background-color: var(--color-bg-muted);
}

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

/* Toggle Switch (Checkbox) */
.toggle {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    cursor: pointer;
    user-select: none;
}

.toggle input[type="checkbox"] {
    appearance: none;
    width: 18px;
    height: 18px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--duration-fast);
    position: relative;
}

.toggle input[type="checkbox"]:hover {
    border-color: var(--color-primary);
}

.toggle input[type="checkbox"]:checked {
    background: var(--color-primary);
    border-color: var(--color-primary);
}

.toggle input[type="checkbox"]:checked::after {
    content: '';
    position: absolute;
    left: 5px;
    top: 2px;
    width: 5px;
    height: 9px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.toggle__slider {
    display: none;
}

.toggle__label {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-secondary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    font-family: var(--font-sans);
    font-size: 14px;
    font-weight: 600;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--duration-base) var(--ease-out);
    text-decoration: none;
}

.btn--outline {
    background: var(--color-bg-subtle);
    border: 1px solid transparent;
    color: var(--color-text-secondary);
}

.btn--outline:hover {
    background: var(--color-bg-muted);
    color: var(--color-text);
}

.btn--outline.active {
    background: var(--color-saved-bg);
    color: var(--color-saved);
    border-color: var(--color-saved-border);
}

.btn--outline.active svg {
    fill: currentColor;
}

.btn--ghost {
    background: transparent;
    color: var(--color-text-secondary);
    padding: var(--space-2) var(--space-3);
}

.btn--ghost:hover {
    color: var(--color-text);
    background: var(--color-bg-subtle);
}

/* ========================================
   Main Content
   ======================================== */
.main {
    flex: 1;
    padding: 0 var(--space-6) var(--space-8);
    max-width: var(--max-width);
    margin: 0 auto;
    width: 100%;
}

/* Loading State */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-16) 0;
}

.loading__spinner {
    width: 36px;
    height: 36px;
    border: 3px solid var(--color-bg-muted);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading__text {
    margin-top: var(--space-4);
    font-size: 14px;
    color: var(--color-text-muted);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: var(--space-16) var(--space-6);
}

.empty-state__icon {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--space-4);
    color: var(--color-text-muted);
    opacity: 0.5;
}

.empty-state__title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-2);
}

.empty-state__text {
    font-size: 14px;
    color: var(--color-text-muted);
}

/* ========================================
   Conference Cards Grid
   ======================================== */
.conferences {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--space-5);
}

@media (max-width: 640px) {
    .conferences {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   Conference Card - Modern Event Card
   ======================================== */
.conf-card {
    display: flex;
    flex-direction: column;
    background: var(--card-bg, var(--color-bg-elevated));
    border: 1px solid var(--card-border, var(--border-color));
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--duration-base) var(--ease-out);
    position: relative;
    animation: cardEnter 0.4s var(--ease-out) backwards;
}

@keyframes cardEnter {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.conf-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--card-accent, var(--color-text-muted));
    opacity: 0;
    transition: opacity var(--duration-base);
}

.conf-card:hover {
    border-color: var(--card-accent, var(--color-primary));
    box-shadow: var(--shadow-lg), 0 0 0 1px var(--card-accent, var(--color-primary));
    transform: translateY(-3px);
}

.conf-card:hover::before {
    opacity: 1;
}

/* Card urgency states */
.conf-card--urgent {
    --card-accent: var(--color-urgent);
    border-color: var(--color-urgent-border);
    background: var(--color-urgent-bg);
}

.conf-card--soon {
    --card-accent: var(--color-soon);
    border-color: var(--color-soon-border);
    background: var(--color-soon-bg);
}

.conf-card--open {
    --card-accent: var(--color-open);
}

.conf-card--expired {
    opacity: 0.5;
    filter: grayscale(0.3);
}

.conf-card--tba {
    border-style: dashed;
    background: repeating-linear-gradient(
        -45deg,
        var(--color-bg-elevated),
        var(--color-bg-elevated) 10px,
        var(--color-bg-subtle) 10px,
        var(--color-bg-subtle) 11px
    );
}

/* Saved State */
.conf-card--saved {
    box-shadow: 0 0 0 2px var(--color-saved-border), var(--shadow-md);
}

/* Card Header */
.conf-card__header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--space-3);
    padding: var(--space-5) var(--space-5) 0;
}

.conf-card__flag {
    font-size: 28px;
    line-height: 1;
    flex-shrink: 0;
    filter: drop-shadow(0 2px 3px rgba(0,0,0,0.15));
}

.conf-card__actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.conf-card__cal-btn,
.conf-card__save-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    font-size: 13px;
    color: var(--color-text-secondary);
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--duration-fast);
}

.conf-card__cal-btn:hover,
.conf-card__save-btn:hover {
    background: var(--color-bg-muted);
    color: var(--color-text);
    border-color: var(--color-text-muted);
}

.conf-card__save-btn.saved {
    color: var(--color-saved);
    border-color: var(--color-saved-border);
    background: var(--color-saved-bg);
}

.conf-card__save-btn.saved svg path {
    fill: currentColor;
}

.conf-card__cal-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Card Body */
.conf-card__body {
    flex: 1;
    padding: var(--space-4) var(--space-5);
}

.conf-card__title {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.4;
    letter-spacing: -0.01em;
    margin-bottom: var(--space-3);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.conf-card__deadline {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-bottom: var(--space-3);
    font-size: 14px;
    color: var(--color-text-secondary);
}

.conf-card__deadline-label {
    font-size: 12px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.conf-card__deadline-value {
    font-family: var(--font-mono);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text);
}

.conf-card__countdown {
    margin-left: auto;
    font-size: 12px;
    font-weight: 600;
    color: var(--card-accent, var(--color-text-muted));
    background: var(--color-bg-subtle);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
}

.conf-card--urgent .conf-card__countdown {
    background: var(--color-urgent-bg);
    color: var(--color-urgent);
}

.conf-card--soon .conf-card__countdown {
    background: var(--color-soon-bg);
    color: #B45309;
}

.conf-card__meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
}

.conf-card__location,
.conf-card__date {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 13px;
    color: var(--color-text-muted);
}

.conf-card__location svg,
.conf-card__date svg {
    opacity: 0.7;
}

/* Card Footer */
.conf-card__footer {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-5);
    border-top: var(--border);
}

.conf-card__topics {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    flex: 1;
}

.conf-card__topic {
    display: inline-flex;
    align-items: center;
    font-size: 11px;
    font-weight: 500;
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-full);
    background: var(--color-bg-subtle);
    color: var(--color-text-secondary);
}

/* Topic-specific colors - Vibrant & Bold */
.conf-card__topic--ml,
.tag--ml {
    background: linear-gradient(135deg, #8B5CF6 0%, #7C3AED 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(139, 92, 246, 0.3);
}
.conf-card__topic--nlp,
.tag--nlp {
    background: linear-gradient(135deg, #06B6D4 0%, #0891B2 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(6, 182, 212, 0.3);
}
.conf-card__topic--cv,
.tag--cv {
    background: linear-gradient(135deg, #EC4899 0%, #DB2777 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(236, 72, 153, 0.3);
}
.conf-card__topic--ai,
.tag--ai {
    background: linear-gradient(135deg, #6366F1 0%, #4F46E5 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(99, 102, 241, 0.3);
}
.conf-card__topic--dl,
.tag--dl {
    background: linear-gradient(135deg, #10B981 0%, #059669 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(16, 185, 129, 0.3);
}
.conf-card__topic--rl,
.tag--rl {
    background: linear-gradient(135deg, #F59E0B 0%, #D97706 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(245, 158, 11, 0.3);
}
.conf-card__topic--robotics,
.tag--robotics {
    background: linear-gradient(135deg, #EF4444 0%, #DC2626 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(239, 68, 68, 0.3);
}
.conf-card__topic--speech,
.tag--speech {
    background: linear-gradient(135deg, #14B8A6 0%, #0D9488 100%);
    color: white;
    box-shadow: 0 2px 4px rgba(20, 184, 166, 0.3);
}

/* Status Badge */
.status-badge {
    display: none;
    align-items: center;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-full);
    flex-shrink: 0;
}

.status-badge--urgent {
    display: inline-flex;
    background: var(--color-urgent);
    color: white;
}

.status-badge--soon {
    display: inline-flex;
    background: var(--color-soon);
    color: white;
}

.status-badge--tba {
    display: inline-flex;
    background: transparent;
    color: var(--color-text-muted);
    border: 1px dashed var(--color-text-muted);
}

.status-badge--expired {
    display: inline-flex;
    background: var(--color-expired);
    color: white;
}

/* Card Link */
.conf-card__link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-subtle);
    border: 1px solid transparent;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    color: var(--color-text-secondary);
    font-size: 13px;
    font-weight: 500;
    transition: all var(--duration-fast);
}

.conf-card__link:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
}

.conf-card__link:hover svg {
    transform: translate(2px, -2px);
}

.conf-card__link svg {
    transition: transform var(--duration-fast);
}

/* Staggered card animations */
.conf-card:nth-child(1) { animation-delay: 0.02s; }
.conf-card:nth-child(2) { animation-delay: 0.04s; }
.conf-card:nth-child(3) { animation-delay: 0.06s; }
.conf-card:nth-child(4) { animation-delay: 0.08s; }
.conf-card:nth-child(5) { animation-delay: 0.10s; }
.conf-card:nth-child(6) { animation-delay: 0.12s; }
.conf-card:nth-child(7) { animation-delay: 0.14s; }
.conf-card:nth-child(8) { animation-delay: 0.16s; }
.conf-card:nth-child(9) { animation-delay: 0.18s; }
.conf-card:nth-child(10) { animation-delay: 0.20s; }
.conf-card:nth-child(n+11) { animation-delay: 0.22s; }

/* ========================================
   Footer - Professional Multi-Column
   ======================================== */
.footer {
    margin-top: var(--space-16);
    padding: var(--space-12) 0 var(--space-8);
    background: var(--color-text);
    color: white;
}

.footer__inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-10);
    margin-bottom: var(--space-10);
}

@media (max-width: 900px) {
    .footer__grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-8);
    }
}

@media (max-width: 600px) {
    .footer__grid {
        grid-template-columns: 1fr;
    }
}

.footer__brand {
    max-width: 300px;
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: 18px;
    font-weight: 600;
    margin-bottom: var(--space-4);
    color: white;
}

.footer__logo svg {
    stroke: var(--color-primary);
}

.footer__tagline {
    font-size: 14px;
    line-height: 1.6;
    color: rgba(255,255,255,0.7);
    margin-bottom: var(--space-5);
}

.footer__social {
    display: flex;
    gap: var(--space-3);
}

.footer__social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: var(--radius-md);
    color: rgba(255,255,255,0.7);
    transition: all var(--duration-fast);
}

.footer__social-link:hover {
    background: var(--color-primary);
    color: white;
    transform: translateY(-2px);
}

.footer__column {
    min-width: 0;
}

.footer__heading {
    font-size: 14px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: white;
    margin-bottom: var(--space-5);
}

.footer__links {
    list-style: none;
}

.footer__links li {
    margin-bottom: var(--space-3);
}

.footer__links a {
    font-size: 14px;
    color: rgba(255,255,255,0.7);
    transition: color var(--duration-fast);
}

.footer__links a:hover {
    color: white;
}

.footer__bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-8);
    border-top: 1px solid rgba(255,255,255,0.1);
}

@media (max-width: 600px) {
    .footer__bottom {
        flex-direction: column;
        gap: var(--space-4);
        text-align: center;
    }
}

.footer__copyright {
    font-size: 13px;
    color: rgba(255,255,255,0.5);
}

.footer__legal {
    display: flex;
    gap: var(--space-6);
}

.footer__legal a {
    font-size: 13px;
    color: rgba(255,255,255,0.5);
    transition: color var(--duration-fast);
}

.footer__legal a:hover {
    color: white;
}

/* Simple footer fallback */
.footer p {
    text-align: center;
    color: rgba(255,255,255,0.7);
    font-size: 14px;
}

.footer__update {
    text-align: center;
    font-family: var(--font-mono);
    font-size: 12px;
    color: rgba(255,255,255,0.5);
    margin-top: var(--space-2);
}

/* ========================================
   Theme Toggle
   ======================================== */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--color-bg-subtle);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--duration-fast);
}

.theme-toggle:hover {
    background: var(--color-bg-muted);
    color: var(--color-text);
}

.theme-toggle:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 2px var(--color-primary-subtle);
}

.theme-toggle__icon {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Sun icon (shown in light mode) */
.theme-toggle__sun {
    display: flex;
}

/* Moon icon (shown in dark mode) */
.theme-toggle__moon {
    display: none;
}

/* In dark mode, show moon and hide sun */
[data-theme="dark"] .theme-toggle__sun {
    display: none;
}

[data-theme="dark"] .theme-toggle__moon {
    display: flex;
}

/* ========================================
   Authentication Components
   ======================================== */
.auth-container {
    position: relative;
}

.auth-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: var(--color-bg-subtle);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    font-size: 14px;
    cursor: pointer;
    transition: all var(--duration-fast);
}

.auth-btn:hover {
    background: var(--color-bg-muted);
    color: var(--color-text);
}

.auth-btn.authenticated {
    background: var(--color-primary-subtle);
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.auth-btn__text {
    max-width: 100px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.auth-dropdown {
    position: absolute;
    top: calc(100% + var(--space-2));
    right: 0;
    min-width: 200px;
    background: var(--color-bg-elevated);
    border: var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    z-index: 200;
}

.auth-user {
    padding: var(--space-4);
    border-bottom: var(--border);
    font-size: 14px;
    color: var(--color-text);
    word-break: break-all;
}

.auth-logout {
    display: block;
    width: 100%;
    padding: var(--space-4);
    text-align: left;
    font-size: 14px;
    color: var(--color-text-secondary);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: all var(--duration-fast);
}

.auth-logout:hover {
    background: var(--color-bg-subtle);
    color: var(--color-urgent);
}

/* ========================================
   Login Modal
   ======================================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    padding: var(--space-4);
}

.modal {
    position: relative;
    width: 100%;
    max-width: 400px;
    background: var(--color-bg-elevated);
    border: var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    animation: modalEnter 0.3s var(--ease-out);
}

@keyframes modalEnter {
    from {
        opacity: 0;
        transform: scale(0.95) translateY(-10px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal__close {
    position: absolute;
    top: var(--space-4);
    right: var(--space-4);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    transition: all var(--duration-fast);
}

.modal__close:hover {
    background: var(--color-bg-subtle);
    color: var(--color-text);
}

.modal__content {
    padding: var(--space-8);
}

.modal__title {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--space-2);
    text-align: center;
}

.modal__subtitle {
    font-size: 14px;
    color: var(--color-text-secondary);
    text-align: center;
    margin-bottom: var(--space-6);
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.login-form__input {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-subtle);
    border: var(--border);
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 15px;
    color: var(--color-text);
    transition: all var(--duration-fast);
}

.login-form__input::placeholder {
    color: var(--color-text-muted);
}

.login-form__input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-subtle);
}

.login-form__submit {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-3) var(--space-6);
    background: var(--color-primary);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 15px;
    font-weight: 600;
    color: white;
    cursor: pointer;
    transition: all var(--duration-fast);
}

.login-form__submit:hover:not(:disabled) {
    background: var(--color-primary-hover);
    box-shadow: var(--shadow-glow);
}

.login-form__submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.login-form__message {
    padding: var(--space-3);
    border-radius: var(--radius-md);
    font-size: 14px;
    text-align: center;
}

.login-form__message--success {
    background: var(--color-open-bg);
    color: #065F46;
    border: 1px solid var(--color-open-border);
}

.login-form__message--error {
    background: var(--color-urgent-bg);
    color: #991B1B;
    border: 1px solid var(--color-urgent-border);
}

/* ========================================
   Utilities
   ======================================== */
.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    .header__inner {
        padding: 0 var(--space-4);
    }

    .filters {
        margin-left: var(--space-4);
        margin-right: var(--space-4);
    }

    .main {
        padding: 0 var(--space-4) var(--space-8);
    }
}

@media (max-width: 768px) {
    .header {
        height: auto;
        padding: var(--space-4) 0;
    }

    .header__inner {
        flex-direction: column;
        height: auto;
        gap: var(--space-4);
    }

    .header__brand {
        width: 100%;
        justify-content: center;
    }

    .header__stats {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }

    .filters {
        flex-direction: column;
        align-items: stretch;
    }

    .filters__main {
        justify-content: center;
    }

    .filters__toggles {
        margin-left: 0;
        justify-content: center;
    }

    .dropdown {
        width: calc(100vw - var(--space-8));
        left: 50%;
        transform: translateX(-50%) translateY(-8px);
    }

    .dropdown.open {
        transform: translateX(-50%) translateY(0);
    }
}

@media (max-width: 480px) {
    .conf-card__title {
        font-size: 14px;
    }

    .filter-select {
        width: 100%;
    }
}

/* ========================================
   Print Styles
   ======================================== */
@media print {
    body::before { display: none; }
    .header, .filters, .btn { display: none; }
    .conf-card { box-shadow: none; border: 1px solid #000; }
}