/* ================= CSS VARIABLES ================= */
:root {
    /* 1. MẶC ĐỊNH: MIDNIGHT GLASSMORPHISM (MÀU TÍM) */
    --bg-color: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
    --text-color: #ffffff;
    --font-heading: 'Cinzel', serif;
    --font-body: 'Jost', sans-serif;
    --nav-color: rgba(255,255,255,0.6);
    --nav-hover: #fff;
    --profile-radius: 50%;
    --profile-border: 2px solid rgba(255, 255, 255, 0.2);
    --profile-filter: none;
    --profile-bg: rgba(255, 255, 255, 0.05);
    --profile-shadow: none;
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: 1px solid rgba(255, 255, 255, 0.1);
    --card-radius: 16px;
    --card-shadow: none;
    --card-backdrop: blur(12px);
    --card-text: #fff;
    --icon-color: rgba(255,255,255,0.8);
    --arrow-color: rgba(255,255,255,0.4);
    --card-hover-bg: rgba(255, 255, 255, 0.15);
    --card-hover-text: #fff;
    --card-hover-transform: scale(1.02);
}

body.theme-original {
    /* 2. ORIGINAL LUXURY (MÀU ĐEN) */
    --bg-color: #050505;
    --text-color: #ffffff;
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Montserrat', sans-serif;
    --nav-color: #666;
    --nav-hover: #fff;
    --profile-radius: 50%;
    --profile-border: 1px solid #222;
    --profile-filter: none;
    --profile-bg: transparent;
    --profile-shadow: none;
    --card-bg: #111;
    --card-border: 1px solid #1a1a1a;
    --card-radius: 12px;
    --card-shadow: none;
    --card-backdrop: none;
    --card-text: #eee;
    --icon-color: #eee;
    --arrow-color: #444;
    --card-hover-bg: #ffffff;
    --card-hover-text: #000000;
    --card-hover-transform: scale(1.02);
}

body.theme-quiet-luxury {
    /* 3. QUIET LUXURY (SÁNG BO GÓC) */
    --bg-color: #F5F2EB;
    --text-color: #3C3633;
    --font-heading: 'Cormorant Garamond', serif;
    --font-body: 'Outfit', sans-serif;
    --nav-color: #8A817C;
    --nav-hover: #3C3633;
    --profile-radius: 50%;
    --profile-border: none;
    --profile-filter: none;
    --profile-bg: transparent;
    --profile-shadow: 0 10px 25px rgba(60, 54, 51, 0.15);
    --card-bg: #FFFFFF;
    --card-border: 1px solid transparent;
    --card-radius: 20px;
    --card-shadow: 0 4px 15px rgba(0,0,0,0.03);
    --card-backdrop: none;
    --card-text: #3C3633;
    --icon-color: #8A817C;
    --arrow-color: #D5CDC4;
    --card-hover-bg: #FFFFFF;
    --card-hover-text: #3C3633;
    --card-hover-transform: translateY(-3px);
}

body.theme-high-fashion {
    /* 4. HIGH FASHION (TRẮNG VUÔNG VẮN) */
    --bg-color: #ffffff;
    --text-color: #000000;
    --font-heading: 'Bodoni Moda', serif;
    --font-body: 'Inter', sans-serif;
    --nav-color: #000;
    --nav-hover: #000;
    --profile-radius: 0;
    --profile-border: none;
    --profile-filter: grayscale(100%);
    --profile-bg: transparent;
    --profile-shadow: none;
    --card-bg: transparent;
    --card-border: 1px solid #000;
    --card-radius: 0;
    --card-shadow: none;
    --card-backdrop: none;
    --card-text: #000;
    --icon-color: #000;
    --arrow-color: #000;
    --card-hover-bg: #000;
    --card-hover-text: #fff;
    --card-hover-transform: scale(1.02);
}

/* ================= CSS CẤU TRÚC (GIỮ NGUYÊN) ================= */
* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

body {
    background: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-body);
    line-height: 1.6; display: flex; justify-content: center; overflow-x: hidden; min-height: 100vh;
    transition: background 0.5s ease, color 0.5s ease;
}

.app-container {
    width: 100%; max-width: 480px; min-height: 100vh; padding: 40px 24px;
    display: flex; flex-direction: column; opacity: 0; transform: translateY(15px); transition: all 1s ease;
}
.app-container.visible { opacity: 1; transform: translateY(0); }

header { text-align: center; margin-bottom: 45px; }

.top-nav { display: flex; justify-content: center; gap: 24px; margin-bottom: 35px; }
.top-nav a { color: var(--nav-color); text-decoration: none; font-size: 11px; text-transform: uppercase; letter-spacing: 2px; font-weight: 500; transition: color 0.3s ease; }
.top-nav a:hover { color: var(--nav-hover); text-shadow: 0 0 8px rgba(255,255,255,0.3); } /* Thêm hiệu ứng sáng nhẹ khi di chuột */

.profile-img {
    width: 115px; height: 115px; border-radius: var(--profile-radius); object-fit: cover;
    margin-bottom: 20px; border: var(--profile-border); filter: var(--profile-filter);
    background: var(--profile-bg); box-shadow: var(--profile-shadow); padding: 4px; transition: all 0.5s ease;
}

.brand-name { font-family: var(--font-heading); font-size: 32px; font-weight: 400; letter-spacing: 2px; transition: all 0.5s ease; }
.tagline { font-size: 12px; opacity: 0.7; text-transform: uppercase; letter-spacing: 3px; font-weight: 300; }

.social-links { display: flex; flex-direction: column; gap: 14px; flex-grow: 1; }

.link-card {
    display: flex; align-items: center; background: var(--card-bg); border: var(--card-border);
    padding: 18px 24px; border-radius: var(--card-radius); text-decoration: none; color: var(--card-text);
    box-shadow: var(--card-shadow); backdrop-filter: var(--card-backdrop); -webkit-backdrop-filter: var(--card-backdrop);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.link-card i:first-child { font-size: 20px; width: 30px; color: var(--icon-color); transition: all 0.3s ease; }
.link-card span { flex-grow: 1; margin-left: 15px; font-size: 14px; font-weight: 400; text-transform: uppercase; letter-spacing: 1px; }
.arrow { font-size: 12px; color: var(--arrow-color); transition: transform 0.3s ease; }

.link-card:active, .link-card:hover { background: var(--card-hover-bg); color: var(--card-hover-text); transform: var(--card-hover-transform); }
.link-card:active .arrow, .link-card:hover .arrow { color: var(--card-hover-text); transform: translateX(5px); }
.link-card:active i:first-child, .link-card:hover i:first-child { color: var(--card-hover-text); }

/* BỘ CHỌN THEME Ở FOOTER */
footer { margin-top: 50px; text-align: center; padding-bottom: 20px; }
.theme-selector { display: flex; justify-content: center; gap: 12px; margin-bottom: 20px; }
.theme-btn { width: 24px; height: 24px; border-radius: 50%; cursor: pointer; transition: transform 0.2s ease, box-shadow 0.2s ease; }
.theme-btn:hover { transform: scale(1.1); }
.theme-btn.active { box-shadow: 0 0 0 2px var(--bg-color), 0 0 0 4px var(--text-color); }
.copyright { font-size: 10px; opacity: 0.5; letter-spacing: 2px; }