/* Giao diện hệ thống font Inter */
* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; }
body { background-color: #f4f6fc; color: #1e1b4b; }

/* Bố cục chia hai cột ứng dụng */
.app-layout { display: flex; min-height: 100vh; }

/* SIDEBAR TRÁI CỐ ĐỊNH */
.sidebar-left {
    width: 260px; background-color: #1e1b4b; color: white;
    display: flex; flex-direction: column; padding: 24px 16px;
    position: fixed; height: 100vh; left: 0; top: 0; z-index: 100;
}
.sidebar-left .logo {
    display: flex; align-items: center; gap: 10px; font-size: 22px;
    font-weight: 800; padding: 0 10px 32px; color: white;
}
.nav-menu { display: flex; flex-direction: column; gap: 6px; flex: 1; }
.nav-item {
    display: flex; align-items: center; gap: 12px; padding: 12px 16px;
    color: #94a3b8; text-decoration: none; border-radius: 12px;
    font-weight: 600; font-size: 15px; transition: all 0.2s;
}
.nav-item:hover, .nav-item.active { background-color: #4f46e5; color: white; }
.menu-divider { font-size: 11px; text-transform: uppercase; color: #64748b; font-weight: 700; margin: 20px 0 5px 12px; letter-spacing: 0.5px; }
.sidebar-bottom { background: rgba(255,255,255,0.04); padding: 14px; border-radius: 14px; margin-top: auto; }
.level-info { display: flex; justify-content: space-between; font-size: 13px; font-weight: 500; }
.progress-bar-small { height: 6px; background: rgba(255,255,255,0.1); border-radius: 3px; margin: 8px 0; overflow: hidden; }
.progress-fill-small { height: 100%; background: #6366f1; }
.streak-info { font-size: 13px; font-weight: 600; color: #f59e0b; }
.btn-logout { display: block; text-align: center; color: #f87171; text-decoration: none; margin-top: 12px; font-size: 14px; font-weight: 500; }

/* NỘI DUNG CHÍNH BÊN PHẢI */
.main-content { margin-left: 260px; flex: 1; padding: 40px 48px; display: flex; flex-direction: column; min-width: 0; }
.welcome-bar h1 { font-size: 28px; font-weight: 700; color: #1e1b4b; }
.welcome-bar p { color: #6b7280; font-size: 15px; margin-top: 4px; }

/* Thống kê học tập dạng hàng ngang */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin: 24px 0; }
.stat-card { background: white; padding: 16px 20px; border-radius: 16px; border: 1px solid #e2e8f0; display: flex; align-items: center; gap: 16px; }
.st-icon { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 20px; }
.st-icon.icon-purple { background: #e0e7ff; color: #6366f1; }
.st-icon.icon-orange { background: #fef3c7; color: #f59e0b; }
.st-icon.icon-green { background: #d1fae5; color: #10b981; }
.st-icon.icon-gold { background: #fff7ed; color: #ea580c; }
.st-label { font-size: 13px; color: #6b7280; display: block; font-weight: 500; }
.st-val { font-size: 22px; font-weight: 700; color: #1e1b4b; }

/* Tiến trình học tập */
.progress-banner { background: white; padding: 20px; border-radius: 16px; border: 1px solid #e2e8f0; margin-bottom: 24px; }
.banner-header { display: flex; justify-content: space-between; font-weight: 600; font-size: 14px; }
.banner-value { color: #6366f1; }
.banner-subtitle { font-size: 15px; font-weight: 700; margin: 4px 0 12px; }
.bar-bg { height: 12px; background: #e2e8f0; border-radius: 6px; overflow: hidden; }
.bar-fill { height: 100%; background: #6366f1; border-radius: 6px; }

/* Từ vựng trong ngày */
.word-of-the-day { background: #6366f1; color: white; padding: 28px; border-radius: 20px; margin-bottom: 24px; position: relative; }
.wotd-badge { font-size: 11px; font-weight: 700; background: rgba(255,255,255,0.2); width: fit-content; padding: 4px 10px; border-radius: 20px; margin-bottom: 16px; }
.wotd-main { display: flex; justify-content: space-between; align-items: flex-start; }
.wotd-main h2 { font-size: 32px; font-weight: 800; }
.wotd-ipa { font-size: 16px; opacity: 0.8; margin-top: 2px; }
.btn-audio { background: rgba(255,255,255,0.2); border: none; width: 40px; height: 40px; border-radius: 50%; color: white; font-size: 16px; cursor: pointer; display: flex; align-items: center; justify-content: center; }
.wotd-def { font-size: 16px; margin: 16px 0 8px; font-weight: 500; }
.wotd-example { font-size: 14px; opacity: 0.8; font-style: italic; }

/* GIAO DIỆN ADMIN FORM & BẢNG DỮ LIỆU */
.admin-card { background: white; padding: 24px; border-radius: 16px; border: 1px solid #e2e8f0; }
.admin-card h3 { font-size: 16px; font-weight: 700; margin-bottom: 16px; color: #1e1b4b; }
.inline-form { display: flex; gap: 12px; }
.form-input, .form-input select { flex: 1; padding: 12px 16px; border: 1px solid #cbd5e1; border-radius: 10px; font-size: 14px; outline: none; }
.form-input:focus { border-color: #6366f1; }
.btn-primary-action { background: #6366f1; color: white; border: none; padding: 12px 24px; border-radius: 10px; font-weight: 600; cursor: pointer; transition: 0.2s; }
.btn-primary-action:hover { background: #4f46e5; }

.grid-form { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label { font-size: 13px; font-weight: 600; color: #475569; }
.form-textarea { padding: 12px; border: 1px solid #cbd5e1; border-radius: 10px; min-height: 80px; font-size: 14px; outline: none; width: 100%; }
.full-width { grid-column: span 2; }

/* Bảng dữ liệu */
.data-table { width: 100%; border-collapse: collapse; text-align: left; margin-top: 8px; }
.data-table th { background: #f8fafc; padding: 14px; font-size: 13px; font-weight: 600; color: #64748b; border-bottom: 1px solid #e2e8f0; }
.data-table td { padding: 14px; border-bottom: 1px solid #e2e8f0; font-size: 14px; vertical-align: middle; }
.table-img-container { width: 44px; height: 44px; border-radius: 8px; background: #f1f5f9; padding: 4px; display: flex; align-items: center; justify-content: center; }
.table-img-container img { max-width: 100%; max-height: 100%; object-fit: contain; }
.word-main-title { font-weight: 700; color: #1e1b4b; font-size: 15px; }
.word-ipa-sub { font-size: 12px; color: #64748b; }
.badge { font-size: 12px; font-weight: 600; padding: 4px 10px; border-radius: 20px; width: fit-content; display: inline-block; }
.badge.purple { background: #e0e7ff; color: #4f46e5; }
.badge.pink { background: #fce7f3; color: #db2777; }
.badge.green { background: #d1fae5; color: #065f46; }
.btn-edit { color: #2563eb; text-decoration: none; font-weight: 600; margin-right: 10px; }
.btn-delete { color: #dc2626; text-decoration: none; font-weight: 600; }

/* FOOTER ĐƯỢC CHÈN PHÍA DƯỚI CÙNG BÊN PHẢI */
.app-footer { margin-top: auto; padding-top: 24px; border-top: 1px solid #e2e8f0; }
.footer-content { display: flex; justify-content: space-between; font-size: 13px; color: #64748b; }
.footer-links a { color: #64748b; text-decoration: none; margin-left: 16px; }

/* CSS DÀNH RIÊNG CHO TRANG CHỦ INDEX (LANDING PAGE) */
.landing-body { background: #ffffff; }
.landing-header { display: flex; justify-content: space-between; align-items: center; padding: 20px 60px; border-bottom: 1px solid #f1f5f9; }
.landing-logo { display: flex; align-items: center; gap: 8px; font-size: 22px; font-weight: 800; color: #1e1b4b; }
.landing-nav a { margin: 0 16px; text-decoration: none; color: #475569; font-weight: 600; font-size: 15px; }
.landing-nav a.active { color: #6366f1; }
.landing-auth .btn-secondary { text-decoration: none; color: #1e1b4b; font-weight: 600; margin-right: 20px; font-size: 15px; }
.landing-auth .btn-primary { background: #6366f1; color: white; padding: 10px 20px; border-radius: 8px; text-decoration: none; font-weight: 600; font-size: 15px; }
.hero-section { text-align: center; padding: 80px 20px; background: linear-gradient(180deg, #f5f7ff 0%, #ffffff 100%); }
.hero-section h1 { font-size: 44px; font-weight: 800; color: #1e1b4b; line-height: 1.2; }
.text-gradient { background: linear-gradient(to right, #6366f1, #a855f7); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero-section p { color: #64748b; max-width: 640px; margin: 16px auto 0; font-size: 16px; line-height: 1.6; }
.landing-features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; max-width: 1200px; margin: 0 auto 60px; padding: 0 20px; }
.feat-card { background: white; border: 1px solid #e2e8f0; padding: 32px 24px; border-radius: 16px; box-shadow: 0 4px 20px rgba(0,0,0,0.02); }
.feat-icon { width: 48px; height: 48px; font-size: 24px; display: flex; align-items: center; justify-content: center; border-radius: 12px; margin-bottom: 16px; }
.feat-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; color: #1e1b4b; }
.feat-card p { color: #64748b; font-size: 14px; line-height: 1.5; }
/* Tải phông chữ Inter */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* Thiết lập cơ bản cho Header và Footer */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

.landing-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 60px;
    border-bottom: 1px solid #f1f5f9;
    background: #ffffff;
    /* Hiệu ứng ghim trên cùng */
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.landing-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 26px;
    font-weight: 800;
    color: #4f46e5; /* Màu tím đậm cho WordWise */
    text-decoration: none;
}

.landing-nav {
    display: flex;
    gap: 32px;
}

/* Các nút điều hướng mặc định màu đen */
.landing-nav a {
    text-decoration: none;
    color: #1f2937; /* Màu đen xám */
    font-weight: 600;
    font-size: 15px;
    transition: color 0.3s ease;
}

/* Mục nào đang active hoặc được hover sẽ hiện màu tím */
.landing-nav a:hover,
.landing-nav a.active {
    color: #4f46e5;
}

.landing-auth {
    display: flex;
    align-items: center;
    gap: 20px;
}

.landing-auth .btn-secondary {
    text-decoration: none;
    color: #1f2937;
    font-weight: 600;
    font-size: 15px;
}

.landing-auth .btn-primary {
    background: #4f46e5; /* Màu tím cho nút chính */
    color: white;
    padding: 10px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 15px;
    transition: background 0.3s ease;
}

.landing-auth .btn-primary:hover {
    background: #3730a3;
}