/**
 * style.css - 영어 챌린지 메인 스타일시트
 * 위치: /assets/css/style.css
 * Color Scheme: Cosmic + Orange (Kayak-inspired)
 * Design Reference: Kayak comparison-tool style
 *
 * ANTIGRAVITY 효과 선택:
 * 1. 입자 흔적 (Particle Trail) - particle, easy
 * 2. 빛 그라디언트 (Light Gradient) - light, easy
 * 3. 운동량 (Momentum) - gravity, medium
 */

/* ========== CSS 변수 (Cosmic + Orange Theme) ========== */
:root {
    /* Primary Orange Colors (Kayak-inspired) */
    --primary: #FF6F00;
    --primary-dark: #E65100;
    --primary-light: #FF9800;
    --primary-glow: rgba(255, 111, 0, 0.5);

    /* Cosmic Secondary Colors */
    --secondary: #667eea;
    --secondary-dark: #5a67d8;
    --secondary-light: #818cf8;
    --accent: #f093fb;
    --accent-glow: rgba(240, 147, 251, 0.4);

    /* Cosmic Gradient */
    --gradient-cosmic: linear-gradient(135deg, #0f0c29 0%, #302b63 50%, #24243e 100%);
    --gradient-orange: linear-gradient(135deg, #FF6F00 0%, #FF9800 100%);
    --gradient-warm: linear-gradient(135deg, #FF6F00 0%, #f093fb 50%, #667eea 100%);
    --gradient-aurora: linear-gradient(135deg, #FF9800 0%, #FF6F00 50%, #E65100 100%);
    --gradient-card: linear-gradient(145deg, rgba(26, 26, 46, 0.95) 0%, rgba(15, 12, 41, 0.95) 100%);

    /* Background Colors */
    --bg-dark: #0f0c29;
    --bg-medium: #1a1a2e;
    --bg-light: #16213e;
    --bg-card: rgba(26, 26, 46, 0.95);
    --bg-glass: rgba(255, 255, 255, 0.08);

    /* Text Colors */
    --text-white: #ffffff;
    --text-light: #e2e8f0;
    --text-gray: #94a3b8;
    --text-muted: #64748b;

    /* Glow Effects */
    --glow-primary: rgba(255, 111, 0, 0.5);
    --glow-secondary: rgba(102, 126, 234, 0.5);
    --glow-accent: rgba(240, 147, 251, 0.4);

    /* Status Colors */
    --success: #10b981;
    --success-glow: rgba(16, 185, 129, 0.5);
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;

    /* Layout */
    --container-max: 1400px;
    --header-height: 80px;
    --border-radius: 16px;
    --border-radius-sm: 8px;
    --border-radius-lg: 24px;
    --border-radius-xl: 32px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 40px var(--glow-primary);
    --shadow-orange: 0 8px 32px rgba(255, 111, 0, 0.3);
}

/* ========== 리셋 & 기본 스타일 ========== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-dark);
    color: var(--text-light);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary);
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul, ol {
    list-style: none;
}

/* ========== 유틸리티 클래스 ========== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
}

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

.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: var(--text-white);
    padding: 12px 24px;
    border-radius: var(--border-radius);
    z-index: 9999;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 10px;
}

/* ========== 파티클 캔버스 배경 ========== */
#particle-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: 0.3;
}

/* ========== 헤더 ========== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(15, 12, 41, 0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 111, 0, 0.15);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.site-header.scrolled {
    background: rgba(15, 12, 41, 0.98);
    box-shadow: 0 4px 30px rgba(255, 111, 0, 0.1);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

/* 로고 */
.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    z-index: 1001;
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
}

.logo-icon svg {
    width: 100%;
    height: 100%;
}

.logo-text {
    font-size: 20px;
    font-weight: 800;
    color: var(--text-white);
    font-family: 'Poppins', sans-serif;
    letter-spacing: -0.5px;
}

/* 메인 네비게이션 */
.main-nav {
    display: flex;
    align-items: center;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-item {
    position: relative;
}

.nav-item > a {
    display: flex;
    align-items: center;
    padding: 12px 20px;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-gray);
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
}

.nav-item > a:hover,
.nav-item.active > a {
    color: var(--text-white);
    background: rgba(255, 111, 0, 0.1);
}

.nav-item.active > a {
    color: var(--primary);
}

/* 드롭다운 메뉴 */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: rgba(26, 26, 46, 0.98);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-lg);
}

.has-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li a {
    display: block;
    padding: 12px 16px;
    font-size: 14px;
    color: var(--text-gray);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.dropdown-menu li a:hover {
    color: var(--text-white);
    background: rgba(255, 111, 0, 0.15);
}

/* 헤더 액션 버튼 */
.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* ========== 버튼 스타일 ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 15px;
    font-weight: 600;
    border-radius: var(--border-radius);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    text-decoration: none;
}

.btn-sm {
    padding: 10px 20px;
    font-size: 14px;
}

.btn-lg {
    padding: 18px 36px;
    font-size: 16px;
}

.btn-primary {
    background: var(--gradient-orange);
    color: var(--text-white);
    box-shadow: 0 4px 20px var(--glow-primary);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px var(--glow-primary);
    color: var(--text-white);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-white);
    border: 1px solid rgba(255, 111, 0, 0.3);
}

.btn-secondary:hover {
    border-color: var(--primary);
    background: rgba(255, 111, 0, 0.1);
    color: var(--text-white);
}

.btn-outline {
    background: transparent;
    color: var(--text-white);
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
    border-color: var(--primary);
    background: rgba(255, 111, 0, 0.1);
    color: var(--text-white);
}

.btn-block {
    width: 100%;
}

.btn-icon {
    width: 48px;
    height: 48px;
    padding: 0;
    border-radius: 50%;
}

/* ========== 모바일 메뉴 토글 ========== */
.mobile-menu-toggle {
    display: none;
    width: 48px;
    height: 48px;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    cursor: pointer;
    z-index: 1001;
}

.hamburger {
    display: flex;
    flex-direction: column;
    gap: 6px;
    width: 24px;
}

.hamburger .line {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text-white);
    border-radius: 2px;
    transition: all var(--transition-normal);
}

.mobile-menu-toggle.active .hamburger .line:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.mobile-menu-toggle.active .hamburger .line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active .hamburger .line:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* 모바일 오버레이 */
.mobile-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    opacity: 0;
    visibility: hidden;
    z-index: 999;
    transition: all var(--transition-normal);
}

.mobile-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* 모바일 네비게이션 */
.mobile-nav {
    position: fixed;
    top: 0;
    right: -320px;
    width: 320px;
    height: 100vh;
    background: var(--bg-medium);
    z-index: 1002;
    display: flex;
    flex-direction: column;
    transition: right var(--transition-normal);
    overflow-y: auto;
}

.mobile-nav.active {
    right: 0;
}

.mobile-nav-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid rgba(255, 111, 0, 0.15);
}

.mobile-nav-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
}

.mobile-nav-close {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.mobile-nav-close svg {
    width: 20px;
    height: 20px;
    color: var(--text-white);
}

.mobile-nav-close:hover {
    background: rgba(255, 111, 0, 0.2);
}

.mobile-nav-list {
    flex: 1;
    padding: 16px;
}

.mobile-nav-list li {
    margin-bottom: 4px;
}

.mobile-nav-list a {
    display: block;
    padding: 14px 16px;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-gray);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.mobile-nav-list a:hover,
.mobile-nav-list a.active {
    color: var(--text-white);
    background: rgba(255, 111, 0, 0.15);
}

.mobile-nav-footer {
    padding: 20px 24px;
    border-top: 1px solid rgba(255, 111, 0, 0.15);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* ========== 메인 컨텐츠 ========== */
.site-main {
    position: relative;
    z-index: 1;
    min-height: calc(100vh - var(--header-height));
    padding-top: var(--header-height);
}

/* ========== 섹션 공통 스타일 ========== */
.section {
    padding: 100px 0;
    position: relative;
}

.section-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(255, 111, 0, 0.15);
    border: 1px solid rgba(255, 111, 0, 0.3);
    border-radius: 50px;
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 20px;
}

.section-badge svg {
    width: 16px;
    height: 16px;
}

.section-title {
    font-size: clamp(32px, 5vw, 48px);
    font-weight: 800;
    color: var(--text-white);
    margin-bottom: 16px;
    line-height: 1.2;
}

.section-desc {
    font-size: 18px;
    color: var(--text-gray);
    max-width: 600px;
    line-height: 1.7;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header .section-desc {
    margin: 0 auto;
}

/* ========== 카드 스타일 (Kayak 비교 도구 스타일) ========== */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 111, 0, 0.15);
    border-radius: var(--border-radius-lg);
    padding: 32px;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 111, 0, 0.1) 0%, transparent 50%);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.card:hover {
    transform: translateY(-8px);
    border-color: rgba(255, 111, 0, 0.4);
    box-shadow: 0 20px 60px rgba(255, 111, 0, 0.15);
}

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

/* 비교 카드 (Kayak 스타일) */
.comparison-card {
    background: var(--bg-card);
    border: 2px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.comparison-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-orange);
}

.comparison-header {
    background: rgba(255, 111, 0, 0.1);
    padding: 20px 24px;
    border-bottom: 1px solid rgba(255, 111, 0, 0.2);
}

.comparison-header h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
}

.comparison-body {
    padding: 24px;
}

.comparison-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.comparison-item:last-child {
    border-bottom: none;
}

.comparison-label {
    font-size: 14px;
    color: var(--text-gray);
}

.comparison-value {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-white);
}

.comparison-value.highlight {
    color: var(--primary);
}

.comparison-footer {
    padding: 20px 24px;
    background: rgba(255, 111, 0, 0.05);
    border-top: 1px solid rgba(255, 111, 0, 0.2);
}

/* 가격 카드 (Kayak 스타일) */
.price-card {
    background: var(--bg-card);
    border: 2px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius-lg);
    padding: 40px 32px;
    text-align: center;
    position: relative;
    transition: all var(--transition-normal);
}

.price-card.featured {
    border-color: var(--primary);
    background: linear-gradient(145deg, rgba(255, 111, 0, 0.1) 0%, var(--bg-card) 100%);
}

.price-card.featured::before {
    content: '추천';
    position: absolute;
    top: -1px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--gradient-orange);
    color: var(--text-white);
    padding: 6px 20px;
    font-size: 12px;
    font-weight: 700;
    border-radius: 0 0 12px 12px;
}

.price-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-orange);
}

.price-name {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 16px;
}

.price-amount {
    font-size: 48px;
    font-weight: 800;
    color: var(--primary);
    font-family: 'Poppins', sans-serif;
    margin-bottom: 8px;
}

.price-amount span {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-gray);
}

.price-desc {
    font-size: 14px;
    color: var(--text-gray);
    margin-bottom: 32px;
}

.price-features {
    text-align: left;
    margin-bottom: 32px;
}

.price-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 0;
    font-size: 14px;
    color: var(--text-light);
}

.price-features li svg {
    width: 20px;
    height: 20px;
    color: var(--success);
    flex-shrink: 0;
}

/* ========== 히어로 슬라이더 ========== */
.hero-slider {
    position: relative;
    height: 100vh;
    min-height: 700px;
    overflow: hidden;
}

.slider-container {
    position: relative;
    width: 100%;
    height: 100%;
}

.slider-track {
    display: flex;
    height: 100%;
    transition: transform 0.5s ease;
}

.slide {
    flex: 0 0 100%;
    height: 100%;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.slide-bg {
    position: absolute;
    inset: 0;
    background: var(--gradient-cosmic);
    z-index: 0;
}

.slide-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 30% 50%, rgba(255, 111, 0, 0.2) 0%, transparent 50%);
}

.slide-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
    padding: 0 24px;
}

.slide-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: rgba(255, 111, 0, 0.2);
    border: 1px solid rgba(255, 111, 0, 0.4);
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-light);
    margin-bottom: 24px;
}

.slide-title {
    font-size: clamp(40px, 7vw, 72px);
    font-weight: 900;
    color: var(--text-white);
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -2px;
}

.slide-title .highlight {
    background: var(--gradient-orange);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.slide-desc {
    font-size: clamp(16px, 2vw, 20px);
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.7;
}

.slide-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

/* 슬라이더 네비게이션 */
.slider-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    color: var(--text-white);
    cursor: pointer;
    transition: all var(--transition-fast);
    z-index: 10;
}

.slider-nav:hover {
    background: var(--gradient-orange);
    box-shadow: var(--shadow-orange);
}

.slider-nav.prev {
    left: 20px;
}

.slider-nav.next {
    right: 20px;
}

.slider-nav svg {
    width: 24px;
    height: 24px;
}

/* 슬라이더 페이지네이션 */
.slider-pagination {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
    z-index: 10;
}

.pagination-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pagination-dot.active {
    background: var(--primary);
    box-shadow: 0 0 20px var(--glow-primary);
}

.pagination-dot:hover {
    background: rgba(255, 255, 255, 0.5);
}

/* ========== 페이지 히어로 (서브페이지용) ========== */
.page-hero {
    padding: 120px 0 80px;
    text-align: center;
    background: linear-gradient(180deg, rgba(255, 111, 0, 0.08) 0%, transparent 100%);
    position: relative;
}

.page-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 111, 0, 0.3), transparent);
}

.page-title {
    font-size: clamp(36px, 6vw, 56px);
    font-weight: 800;
    color: var(--text-white);
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.page-desc {
    font-size: 18px;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ========== 특징/기능 그리드 (Kayak 필터 스타일) ========== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.15);
    border-radius: var(--border-radius-lg);
    padding: 40px 32px;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-orange);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(255, 111, 0, 0.4);
    box-shadow: var(--shadow-orange);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 111, 0, 0.15);
    border-radius: var(--border-radius);
    margin-bottom: 24px;
    font-size: 28px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.7;
}

/* ========== 타임라인 (챌린지 일정) ========== */
.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary), var(--secondary));
}

.timeline-item {
    position: relative;
    padding-bottom: 40px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: -33px;
    top: 0;
    width: 16px;
    height: 16px;
    background: var(--primary);
    border-radius: 50%;
    box-shadow: 0 0 20px var(--glow-primary);
}

.timeline-content {
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius);
    padding: 24px;
}

.timeline-date {
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 8px;
}

.timeline-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 8px;
}

.timeline-desc {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.6;
}

/* ========== 히트맵 스타일 (Kayak 영감) ========== */
.heatmap-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 4px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--border-radius);
}

.heatmap-cell {
    aspect-ratio: 1;
    border-radius: 4px;
    background: rgba(255, 111, 0, 0.1);
    transition: all var(--transition-fast);
}

.heatmap-cell.level-1 {
    background: rgba(255, 111, 0, 0.2);
}

.heatmap-cell.level-2 {
    background: rgba(255, 111, 0, 0.4);
}

.heatmap-cell.level-3 {
    background: rgba(255, 111, 0, 0.6);
}

.heatmap-cell.level-4 {
    background: rgba(255, 111, 0, 0.8);
}

.heatmap-cell.level-5 {
    background: var(--primary);
    box-shadow: 0 0 10px var(--glow-primary);
}

/* ========== 통계 카운터 ========== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 32px;
}

.stat-item {
    text-align: center;
    padding: 32px;
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.15);
    border-radius: var(--border-radius-lg);
    transition: all var(--transition-normal);
}

.stat-item:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 111, 0, 0.4);
}

.stat-number {
    font-size: 48px;
    font-weight: 800;
    color: var(--primary);
    font-family: 'Poppins', sans-serif;
    line-height: 1;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-gray);
    font-weight: 500;
}

/* ========== 후기/리뷰 카드 ========== */
.review-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.15);
    border-radius: var(--border-radius-lg);
    padding: 32px;
    transition: all var(--transition-normal);
}

.review-card:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 111, 0, 0.4);
    box-shadow: var(--shadow-orange);
}

.review-rating {
    display: flex;
    gap: 4px;
    margin-bottom: 16px;
}

.review-rating svg {
    width: 20px;
    height: 20px;
    color: var(--warning);
    fill: var(--warning);
}

.review-content {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 24px;
}

.review-author {
    display: flex;
    align-items: center;
    gap: 12px;
}

.review-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-orange);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
}

.review-info h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-white);
    margin-bottom: 4px;
}

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

/* ========== FAQ 아코디언 ========== */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.15);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.faq-item:hover {
    border-color: rgba(255, 111, 0, 0.4);
}

.faq-item.active {
    border-color: var(--primary);
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.faq-question:hover {
    background: rgba(255, 111, 0, 0.05);
}

.faq-question h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-white);
    flex: 1;
}

.faq-icon {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    transition: transform var(--transition-normal);
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer-content {
    padding: 0 24px 24px;
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.7;
}

/* ========== 폼 스타일 ========== */
.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-white);
    margin-bottom: 8px;
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 14px 18px;
    font-size: 15px;
    color: var(--text-white);
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
    font-family: inherit;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(255, 111, 0, 0.15);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--text-muted);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    background-size: 20px;
    padding-right: 48px;
}

/* ========== 푸터 ========== */
.site-footer {
    background: var(--bg-medium);
    border-top: 1px solid rgba(255, 111, 0, 0.15);
}

.footer-top {
    padding: 80px 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(4, 1fr);
    gap: 48px;
}

.footer-brand .footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

.footer-brand .logo-icon {
    width: 40px;
    height: 40px;
}

.footer-brand .footer-logo span {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
}

.footer-desc {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.7;
    margin-bottom: 24px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: all var(--transition-fast);
}

.social-link svg {
    width: 18px;
    height: 18px;
    color: var(--text-gray);
}

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

.social-link:hover svg {
    color: var(--text-white);
}

.footer-links h4 {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 20px;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    font-size: 14px;
    color: var(--text-gray);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-contact ul {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-contact li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 14px;
    color: var(--text-gray);
}

.footer-contact svg {
    width: 18px;
    height: 18px;
    color: var(--primary);
    flex-shrink: 0;
    margin-top: 2px;
}

.footer-bottom {
    padding: 24px 0;
    border-top: 1px solid rgba(255, 111, 0, 0.15);
}

.footer-bottom-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    font-size: 14px;
    color: var(--text-muted);
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: 16px;
}

.footer-legal a {
    font-size: 14px;
    color: var(--text-gray);
}

.footer-legal a:hover {
    color: var(--primary);
}

.footer-legal .divider {
    color: var(--text-muted);
}

/* ========== 맨 위로 버튼 ========== */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-orange);
    border: none;
    border-radius: 50%;
    color: var(--text-white);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: 100;
    box-shadow: var(--shadow-orange);
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(255, 111, 0, 0.4);
}

.scroll-top svg {
    width: 24px;
    height: 24px;
}

/* ========== 알림 배지 (Kayak 스타일) ========== */
.notification-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(255, 111, 0, 0.2);
    border: 1px solid rgba(255, 111, 0, 0.4);
    border-radius: 50px;
    font-size: 13px;
    font-weight: 600;
    color: var(--primary-light);
    animation: pulse-badge 2s infinite;
}

@keyframes pulse-badge {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(255, 111, 0, 0.4);
    }
    50% {
        box-shadow: 0 0 0 8px rgba(255, 111, 0, 0);
    }
}

/* ========== 프로그레스 바 ========== */
.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(255, 111, 0, 0.2);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-orange);
    border-radius: 4px;
    transition: width 0.5s ease;
}

/* ========== 탭 네비게이션 (Kayak 필터 스타일) ========== */
.tabs {
    display: flex;
    gap: 8px;
    padding: 8px;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    margin-bottom: 32px;
}

.tab-btn {
    flex: 1;
    padding: 14px 24px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-gray);
    background: transparent;
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tab-btn:hover {
    color: var(--text-white);
    background: rgba(255, 111, 0, 0.1);
}

.tab-btn.active {
    color: var(--text-white);
    background: var(--gradient-orange);
    box-shadow: var(--shadow-orange);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* ========== 필터 태그 (Kayak 스타일) ========== */
.filter-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 32px;
}

.filter-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-gray);
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.2);
    border-radius: 50px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-tag:hover {
    border-color: rgba(255, 111, 0, 0.4);
    color: var(--text-white);
}

.filter-tag.active {
    background: rgba(255, 111, 0, 0.2);
    border-color: var(--primary);
    color: var(--primary);
}

.filter-tag svg {
    width: 16px;
    height: 16px;
}

/* ========== 플래너 카드 ========== */
.planner-card {
    background: var(--bg-card);
    border: 2px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
}

.planner-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px;
    background: rgba(255, 111, 0, 0.1);
    border-bottom: 1px solid rgba(255, 111, 0, 0.2);
}

.planner-date {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
}

.planner-badge {
    padding: 6px 12px;
    background: var(--gradient-orange);
    border-radius: 50px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-white);
}

.planner-body {
    padding: 24px;
}

.planner-task {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--border-radius-sm);
    margin-bottom: 12px;
    transition: all var(--transition-fast);
}

.planner-task:last-child {
    margin-bottom: 0;
}

.planner-task:hover {
    background: rgba(255, 111, 0, 0.1);
}

.planner-checkbox {
    width: 24px;
    height: 24px;
    border: 2px solid rgba(255, 111, 0, 0.4);
    border-radius: 6px;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.planner-checkbox.checked {
    background: var(--primary);
    border-color: var(--primary);
}

.planner-checkbox.checked svg {
    color: var(--text-white);
}

.planner-task-text {
    flex: 1;
    font-size: 15px;
    color: var(--text-light);
}

.planner-task.completed .planner-task-text {
    text-decoration: line-through;
    color: var(--text-muted);
}

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

/* ========== 영어 표현 카드 ========== */
.expression-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius-lg);
    padding: 32px;
    transition: all var(--transition-normal);
}

.expression-card:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 111, 0, 0.4);
    box-shadow: var(--shadow-orange);
}

.expression-english {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
    font-family: 'Poppins', sans-serif;
    margin-bottom: 8px;
}

.expression-korean {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 16px;
}

.expression-example {
    padding: 16px;
    background: rgba(255, 111, 0, 0.1);
    border-radius: var(--border-radius-sm);
    font-size: 14px;
    color: var(--text-gray);
    font-style: italic;
}

/* ========== 챌린지 진행 상황 ========== */
.challenge-progress {
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.2);
    border-radius: var(--border-radius-lg);
    padding: 32px;
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.challenge-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-white);
}

.challenge-days {
    font-size: 14px;
    color: var(--text-gray);
}

.challenge-days span {
    color: var(--primary);
    font-weight: 700;
}

.challenge-streak {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
}

.streak-day {
    flex: 1;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 111, 0, 0.1);
    border-radius: var(--border-radius-sm);
    font-size: 12px;
    font-weight: 600;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

.streak-day.completed {
    background: var(--primary);
    color: var(--text-white);
}

.streak-day.current {
    border: 2px solid var(--primary);
    color: var(--primary);
}

/* ========== 로딩 스피너 ========== */
.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 111, 0, 0.2);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ========== 토스트 알림 ========== */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    padding: 16px 24px;
    background: var(--bg-card);
    border: 1px solid rgba(255, 111, 0, 0.3);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 9999;
}

.toast.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.toast-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.toast-icon {
    width: 24px;
    height: 24px;
    color: var(--success);
}

.toast-message {
    font-size: 14px;
    color: var(--text-white);
}