/* ==========================================================================
   1. VARIABLES & RESET (SISTEM WARNA BARU)
   ========================================================================== */
:root {
    --warna-putih: #ffffff;
    /* 50% Dominan Latar */
    --warna-hitam: #121212;
    /* 30% Struktur & Teks */
    --warna-abu-soft: #f4f4f4;
    /* Pendukung untuk variasi */
    --warna-merah: #e53935;
    /* 20% Aksen/Tombol Utama */
    --warna-merah-hover: #b71c1c;
    --garis-pembatas: #e0e0e0;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--warna-putih);
    color: var(--warna-hitam);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    padding-top: 80px;
}

.divider {
    border: 0;
    height: 1px;
    background: var(--garis-pembatas);
    margin: 60px auto;
    width: 80%;
    max-width: 800px;
}

/* ==========================================================================
   2. HEADER & NAVIGASI
   ========================================================================== */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(5px);
    border-bottom: 2px solid var(--warna-hitam);
    /* Garis hitam tegas */
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 10%;
    z-index: 1000;
}

header .logo {
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    text-transform: lowercase;
}

header nav {
    display: flex;
    align-items: center;
    gap: 30px;
}

header nav a {
    text-decoration: none;
    color: var(--warna-hitam);
    font-size: 0.95rem;
    font-weight: 600;
    transition: color 0.2s ease;
}

header nav a:hover {
    color: var(--warna-merah);
}

header nav a.active {
    color: var(--warna-merah);
    border-bottom: 2px solid var(--warna-merah);
}

/* Tombol Masuk/Daftar (Aksen Merah) */
header nav a.btn-login {
    background-color: var(--warna-merah);
    color: var(--warna-putih);
    padding: 8px 18px;
    border-radius: 0;
    /* Desain kotak tanpa rounded biar lebih indie/bold */
    transition: background-color 0.2s ease;
}

header nav a.btn-login:hover {
    background-color: var(--warna-merah-hover);
}

nav {
    display: flex;
    gap: 20px;
    /* Memberi jarak antar menu */
    align-items: center;
}

/* ==========================================================================
   3. HERO SECTION
   ========================================================================== */
main {
    max-width: 1100px;
    margin: 0 auto;
    padding: 40px 5%;
}

.hero {
    text-align: center;
    padding: 60px 0;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-family: "Georgia", Georgia, serif;
    font-size: 3.8rem;
    line-height: 1.1;
    font-weight: 900;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

/* Highlight kata penafsir pake warna merah brand */
.hero h1 span {
    color: var(--warna-merah);
}

.hero .sub-slogan {
    font-size: 1.2rem;
    color: #444;
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.hero-buttons a {
    text-decoration: none;
    padding: 14px 30px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.2s ease;
}

.btn-primary {
    background-color: var(--warna-merah);
    color: var(--warna-putih);
}

.btn-primary:hover {
    background-color: var(--warna-merah-hover);
}

.btn-secondary {
    border: 2px solid var(--warna-hitam);
    color: var(--warna-hitam);
}

.btn-secondary:hover {
    background-color: var(--warna-hitam);
    color: var(--warna-putih);
}

/* ==========================================================================
   4. MANIFESTO SECTION
   ========================================================================== */
.manifesto {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.manifesto h2 {
    font-family: "Georgia", Georgia, serif;
    font-size: 2.2rem;
    font-weight: 900;
    margin-bottom: 30px;
}

.manifesto-text {
    font-family: "Georgia", Georgia, serif;
    font-size: 1.3rem;
    color: var(--warna-hitam);
    line-height: 1.8;
    margin-bottom: 20px;
}

/* ==========================================================================
   5. PILAR AKTIVITAS (GRID SECTION)
   ========================================================================== */
.aktivitas h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 2rem;
    font-weight: 800;
}

.grid-aktivitas {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.kartu-aktivitas {
    background-color: var(--warna-putih);
    padding: 30px;
    border: 2px solid var(--warna-hitam);
    /* Border hitam tebal ala zine indie */
    box-shadow: 5px 5px 0px var(--warna-hitam);
    /* Shadow retro kaku */
    transition: transform 0.2s, box-shadow 0.2s;
}

.kartu-aktivitas:hover {
    transform: translate(-2px, -2px);
    box-shadow: 7px 7px 0px var(--warna-merah);
    /* Berubah merah pas di-hover */
}

.kartu-aktivitas h3 {
    margin-bottom: 15px;
    font-size: 1.3rem;
    color: var(--warna-merah);
    /* Judul aktivitas jadi merah */
}

/* ==========================================================================
   6. FOOTER
   ========================================================================== */
footer {
    text-align: center;
    padding: 40px 0;
    border-top: 1px solid var(--garis-pembatas);
    margin-top: 80px;
    color: #666;
    font-size: 0.9rem;
}

/* ==========================================================================
   REKREASI RESPONSIVE (OPTIMASI 90% PENGGUNA MOBILE)
   ========================================================================== */
@media (max-width: 768px) {

    /* 1. Header & Menu Atas di HP */
    header {
        padding: 15px 4%;
        /* Jarak kanan kiri menu dirapetin */
    }

    header .logo {
        font-size: 1.1rem;
        /* Ukuran tulisan "tanda.makna" dikecilin dikit */
    }

    header nav {
        gap: 12px;
        /* Jarak antar menu dirapetin biar gak luber ke bawah */
    }

    header nav a {
        font-size: 0.8rem;
        /* Ukuran font menu dikecilin */
    }

    header nav a.btn-login {
        padding: 6px 12px;
        /* Tombol masuk disesuaiin biar pas di jempol */
    }

    /* 2. Hero Section di HP */
    body {
        padding-top: 70px;
        /* Di HP header lebih tipis, jadi padding body disesuaiin */
    }

    .hero {
        padding: 40px 0;
    }

    .hero h1 {
        font-size: 2.2rem;
        /* Judul gede kemarin bakal kegedean di HP, kita pres jadi 2.2 */
        line-height: 1.2;
    }

    .hero .sub-slogan {
        font-size: 1rem;
        margin-bottom: 30px;
    }

    .hero-buttons {
        flex-direction: column;
        /* Tombolnya numpuk ke bawah, bukan ke samping */
        gap: 12px;
        width: 100%;
        max-width: 280px;
        /* Biar tombolnya gak kelebaran semonitor HP */
        margin: 0 auto;
    }

    /* 3. Manifesto di HP */
    .manifesto h2 {
        font-size: 1.8rem;
    }

    .manifesto-text {
        font-size: 1.1rem;
        text-align: left;
        /* Di HP, teks panjang lebih enak dibaca rata kiri dibanding center */
    }

    /* 4. Aktivitas Grid di HP */
    .grid-aktivitas {
        grid-template-columns: 1fr;
        /* Mutlak jadi 1 kolom ke bawah */
        gap: 20px;
    }

    .kartu-aktivitas {
        box-shadow: 4px 4px 0px var(--warna-hitam);
        /* Shadow disesuaiin biar gak lebay di layar kecil */
    }
}