/* 
 * PaperWhisper Landing Page Styles
 * Design Philosophy: High-Fidelity Skeuomorphism (高保真拟物风)
 */

:root {
    /* 🎨 Colors & Textures */
    --c-paper-bg: #fdfbf7;
    --c-ink: #2c2c2c;
    --c-ink-light: #5a5a5a;
    --c-accent: #e0d8c8;
    --c-highlight: #ffffff;

    /* 🪵 Textures (To be replaced with real images later if needed) */
    --texture-noise: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.05'/%3E%3C/svg%3E");

    /* 🌗 Shadows (The Soul of Skeuomorphism) */
    /* Depth 1: Slight emboss (Paper on desk) */
    --shadow-d1:
        1px 1px 2px rgba(0, 0, 0, 0.05),
        -1px -1px 2px rgba(255, 255, 255, 0.8);

    /* Depth 2: Floating (Card/Photo) */
    --shadow-d2:
        2px 4px 12px rgba(0, 0, 0, 0.08),
        0 0 0 1px rgba(0, 0, 0, 0.02);
    /* Border boundary */

    /* Depth 3: Deep Pressed (Button Active) */
    --shadow-pressed:
        inset 2px 2px 5px rgba(0, 0, 0, 0.1),
        inset -2px -2px 5px rgba(255, 255, 255, 0.7);

    /* 🔡 Fonts */
    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
    --font-serif: "Merriweather", "Georgia", serif;
    --font-hand: "Patrick Hand", "Caveat", cursive;
    /* Need to import these */
}

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

html,
body {
    overflow: hidden;
    /* Prevent default scroll */
    height: 100vh;
    width: 100vw;
}

body {
    background-color: var(--c-paper-bg);
    background-image: var(--texture-noise);
    color: var(--c-ink);
    font-family: var(--font-sans);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-y: hidden;
    /* Handled by JS */
    min-height: 100vh;
}

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

ul {
    list-style: none;
}

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

/* Canvas Background */
#petal-rain {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

/* --- Layout: Sections --- */
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 24px;
}

section {
    height: 100vh;
    width: 100%;
    scroll-snap-align: start;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    overflow: hidden;
    z-index: 1;
    /* Above canvas */
}

/* --- Components: Typography --- */
h1,
h2,
h3 {
    font-family: var(--font-serif);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.text-hand {
    font-family: var(--font-hand);
}

.logo-title {
    font-size: 3.5rem;
    font-weight: 700;
    font-family: var(--font-serif);
    color: var(--c-ink);
    text-shadow:
        1px 1px 0px rgba(255, 255, 255, 0.8),
        -1px -1px 0px rgba(0, 0, 0, 0.1);
    margin-bottom: 1rem;
    cursor: pointer;
}

.section-desc {
    font-family: var(--font-hand);
    font-size: 1.5rem;
    color: var(--c-ink-light);
    max-width: 600px;
    text-align: center;
    line-height: 1.8;
}

/* --- Components: Textures & Cards --- */

/* Leather */
.texture-leather {
    background-color: #3e3b36;
    background-image:
        radial-gradient(rgba(255, 255, 255, 0.1) 1px, transparent 1px),
        radial-gradient(rgba(255, 255, 255, 0.1) 1px, transparent 1px);
    background-size: 20px 20px;
    background-position: 0 0, 10px 10px;
    box-shadow:
        inset 0 0 40px rgba(0, 0, 0, 0.8),
        var(--shadow-d2);
    color: #f0e6d2;
    border-radius: 8px;
    border: 1px solid #2a2825;
}

/* Glass */
.texture-glass {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow:
        0 8px 32px 0 rgba(31, 38, 135, 0.1),
        inset 0 0 0 1px rgba(255, 255, 255, 0.05);
    border-radius: 12px;
}

/* Embossed Paper */
.paper-sheet-embossed {
    background: #fff;
    padding: 3rem;
    box-shadow:
        1px 1px 0px #fff,
        4px 4px 12px rgba(0, 0, 0, 0.08),
        inset 0 0 30px rgba(240, 230, 200, 0.15);
    /* Slight yellowing */
    border-radius: 2px;
    transform: rotate(-1deg);
    max-width: 800px;
    text-align: center;
}

/* Standard Paper Card */
.paper-card {
    background: #fff;
    border-radius: 4px;
    box-shadow: var(--shadow-d2);
    transition: transform 0.3s ease;
}

/* --- Components: Skeuomorphic Button --- */
.btn-skeuo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2.5rem;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--c-ink);
    background: linear-gradient(145deg, #ffffff, #e6e6e6);
    border: 1px solid rgba(0, 0, 0, 0.05);
    border-radius: 12px;
    box-shadow:
        6px 6px 12px #d1d1d1,
        -6px -6px 12px #ffffff;
    cursor: pointer;
    transition: all 0.1s ease;
    user-select: none;
    position: relative;
    overflow: hidden;
}

.btn-skeuo:active {
    background: linear-gradient(145deg, #e6e6e6, #ffffff);
    box-shadow:
        inset 6px 6px 12px #d1d1d1,
        inset -6px -6px 12px #ffffff;
    transform: scale(0.98);
}

/* --- Animations --- */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}