:root {
    --bg-color: #ffffff;
    --text-color: #111111;
    --border-color: #e5e5e5;
    --input-bg: #fafafa;
    --button-bg: #111111;
    --button-text: #ffffff;
    --card-bg: #ffffff;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
}

[data-theme="dark"] {
    --bg-color: #111111;
    --text-color: #f5f5f5;
    --border-color: #262626;
    --input-bg: #1a1a1a;
    --button-bg: #ffffff;
    --button-text: #111111;
    --card-bg: #161616;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    position: relative;
    overflow-x: hidden;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: 1px solid var(--border-color);
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    color: var(--text-color);
    font-size: 16px;
    border-radius: 50%;
}

/* ================================================================
   KOTAK UTAMA (Diberi Animasi Masuk Saat Web Dibuka)
   ================================================================ */
.container {
    width: 100%;
    max-width: 400px;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 32px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    margin-bottom: 60px;
    
    /* Memicu animasi page load */
    animation: webMasuk 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 8px;
    text-align: center;
    letter-spacing: -0.5px;
}

p.subtitle {
    font-size: 14px;
    color: #666666;
    text-align: center;
    margin-bottom: 24px;
}

[data-theme="dark"] p.subtitle {
    color: #a0a0a0;
}

.form-group {
    margin-bottom: 16px;
}

label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    background-color: var(--input-bg);
    color: var(--text-color);
    border-radius: 4px;
    font-size: 16px;
    outline: none;
}

input:focus {
    border-color: var(--text-color);
}

.challenge-container {
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 4px;
    margin-bottom: 16px;
    background-color: var(--input-bg);
}

.challenge-text {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 8px;
    text-align: center;
}

button.btn {
    width: 100%;
    padding: 12px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
}

button.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.status-message {
    font-size: 14px;
    margin-top: 16px;
    text-align: center;
    font-weight: 500;
}

.result-container {
    margin-top: 24px;
    text-align: center;
}

.pairing-code-box {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 4px;
    padding: 16px;
    background-color: var(--input-bg);
    border: 1px dashed var(--border-color);
    border-radius: 4px;
    color: var(--text-color);
}

.hidden {
    display: none !important;
}

/* ================================================================
   LOGIKA ANIMASI UTILITY & FOOTER
   ================================================================ */

/* 1. Animasi untuk memunculkan Box Captcha Tebakan Matematika */
.animated-fade {
    animation: slideDownFadeIn 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes slideDownFadeIn {
    from {
        opacity: 0;
        transform: translateY(-15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 2. Animasi Baru: Efek saat halaman web pertama kali dimuat */
@keyframes webMasuk {
    from {
        opacity: 0;
        transform: translateY(30px); /* Mulai dari agak bawah */
    }
    to {
        opacity: 1;
        transform: translateY(0);   /* Terangkat mulus ke posisi asli */
    }
}

footer {
    position: absolute;
    bottom: 20px;
    text-align: center;
    width: 100%;
    /* Footer juga ikut memudar masuk tipis-tipis */
    animation: webMasuk 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

footer p {
    font-size: 12px;
    color: #888888;
    letter-spacing: 0.5px;
    font-weight: 500;
}

[data-theme="dark"] footer p {
    color: #555555;
}

/* ================================================================
   STYLE KUSTOM ALERT MODAL (MINIMALIS & ANIMASI)
   ================================================================ */

/* Layar latar belakang gelap transparan */
.alert-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.4);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    padding: 20px;
    /* Efek animasi memudar untuk overlay */
    animation: fadeInOverlay 0.2s ease-out forwards;
}

[data-theme="dark"] .alert-overlay {
    background-color: rgba(0, 0, 0, 0.7);
}

/* Kotak isi alert */
.alert-box {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 28px;
    border-radius: 8px;
    width: 100%;
    max-width: 340px;
    text-align: center;
    box-shadow: var(--shadow);
    /* Efek animasi membesar halus saat muncul */
    animation: scaleInAlert 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.alert-box h2 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.5px;
}

.alert-box p {
    font-size: 14px;
    color: #666666;
    margin-bottom: 24px;
    line-height: 1.5;
}

[data-theme="dark"] .alert-box p {
    color: #a0a0a0;
}

/* Tombol konfirmasi di dalam alert */
.alert-btn {
    width: 100%;
    padding: 10px;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

.alert-btn:hover {
    opacity: 0.9;
}

/* @keyframes Animasi Alert */
@keyframes fadeInOverlay {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

/* ================================================================
   STYLE BANNER PEMBERITAHUAN MELAYANG (FLOATING CARD)
   ================================================================ */

.top-nav-bar {
    position: fixed;
    top: 20px; /* Kasih jarak dari atas layar */
    left: 50%;
    transform: translateX(-50%); /* Sentralisasi agar pas di tengah-tengah */
    width: calc(100% - 40px); /* Bikin sela-sela 20px di kanan dan 20px di kiri */
    max-width: 800px; /* Batas lebar maksimal biar gak kelebaran di PC */
    background-color: var(--input-bg);
    border: 1px solid var(--border-color); /* Garis border tipis memutari kotak */
    padding: 14px 24px;
    z-index: 999;
    border-radius: 8px; /* Sudut kotak dibuat melengkung halus */
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

[data-theme="dark"] .top-nav-bar {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.top-nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

.top-nav-content p {
    font-size: 13px;
    line-height: 1.5;
    color: var(--text-color);
    font-weight: 500;
    text-align: left;
}

.close-nav-btn {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 16px;
    cursor: pointer;
    padding: 4px;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0.6;
    transition: opacity 0.2s;
}

.close-nav-btn:hover {
    opacity: 1;
}

/* Penyesuaian jarak body utama agar tidak tertimpa card atas */
body {
    padding-top: 100px !important; 
}

.theme-toggle {
    top: 110px !important; /* Biar tombol dark mode turun di bawah card melayang */
}

/* Animasi menghilangkan banner pas diclose (meluncur ke atas & memudar) */
.nav-fade-out {
    opacity: 0;
    transform: translate(-50%, -30px) scale(0.95) !important;
    pointer-events: none;
}