:root {
    --primary-blue: #007aff; 
    --background-light: #f9f9fb;
    --card-bg: #ffffff; 
    --text-main: #1d1d1f;
    --text-secondary: #6e6e73;
    --border-color: rgba(0, 0, 0, 0.05);
    --header-bg: rgba(255, 255, 255, 0.85);
    --mockup-gradient: linear-gradient(135deg, #e0e0e5, #ffffff);
    --mockup-inner-bg: rgba(255, 255, 255, 0.9);
    --border-radius-main: 18px;
    --border-radius-button: 999px;
}

:root.dark-mode {
    --primary-blue: #0a84ff;
    --background-light: #1c1c1e;
    --card-bg: #2c2c2e;
    --text-main: #f2f2f7;
    --text-secondary: #aeaeb3;
    --border-color: rgba(255, 255, 255, 0.1);
    --header-bg: rgba(28, 28, 30, 0.85);
    --mockup-gradient: linear-gradient(135deg, #242426, #303032);
    --mockup-inner-bg: rgba(44, 44, 46, 0.9);
}

:where(body) {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--background-light); 
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.logo { font-size: 26px; font-weight: 700; letter-spacing: -0.02em; }
h3 { font-size: 32px; font-weight: 700; margin-bottom: 40px; }

.title-large {
    font-size: 72px;
    font-weight: 800;
    letter-spacing: -0.04em;
    margin-bottom: 24px;
}

.subtitle {
    font-size: 28px;
    color: var(--text-secondary);
    margin-bottom: 60px;
    font-weight: 400;
}

.text-center { text-align: center; }

.header {
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--header-bg); 
    backdrop-filter: blur(10px); 
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: background-color 0.3s;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.main-nav {
    display: flex;
    align-items: center;
    flex-grow: 1;
    justify-content: flex-end;
    margin-right: 15px;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    margin-left: 30px;
    transition: color 0.2s ease;
}

.main-nav a:hover { color: var(--primary-blue); }

.cta-link {
    background-color: var(--primary-blue);
    color: var(--card-bg) !important;
    padding: 8px 18px;
    border-radius: var(--border-radius-button);
    font-weight: 600 !important;
    margin-right: 0;
}

#theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-main);
    font-size: 20px; 
    width: 30px;
    height: 30px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    transition: opacity 0.2s;
    flex-shrink: 0;
}

#theme-toggle:hover {
    opacity: 0.7;
}

.button {
    display: inline-block;
    padding: 18px 40px;
    text-decoration: none;
    border-radius: var(--border-radius-button);
    font-weight: 600;
    font-size: 19px;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
}

.button.primary {
    background-color: var(--primary-blue);
    color: var(--card-bg);
    border: 2px solid var(--primary-blue);
}

.button.primary:hover {
    background-color: #0066cc;
    border-color: #0066cc;
    transform: translateY(-1px);
}

.button.secondary {
    background-color: var(--card-bg);
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.button.secondary:hover {
    background-color: var(--primary-blue);
    color: var(--card-bg);
    transform: translateY(-1px);
}

section {
    padding: 120px 0;
}

.hero-section {
    padding-top: 150px;
    padding-bottom: 80px;
}

.info-block {
    opacity: 0; 
    transform: translateY(20px);
    transition: opacity 0.7s cubic-bezier(0.2, 0.8, 0.2, 1), transform 0.7s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.info-block.visible {
    opacity: 1;
    transform: translateY(0);
}

.large-card {
    background-color: var(--card-bg);
    border-radius: 24px;
    max-width: 90%;
    margin: 80px auto;
    padding: 50px 80px; 
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border-color);
    transition: background-color 0.3s, border-color 0.3s;
}

.mockup-container {
    padding-top: 80px;
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 1s cubic-bezier(0.2, 0.8, 0.2, 1), transform 1s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.mockup-container.visible {
    opacity: 1;
    transform: translateY(0);
}

.mockup-card {
    width: 90%;
    max-width: 800px; 
    height: 350px;
    background: var(--mockup-gradient);
    border-radius: 24px;
    margin: 0 auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1); 
    border: 1px solid rgba(255, 255, 255, 0.7); 
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s, border-color 0.3s;
}

.mockup-content {
    background-color: var(--mockup-inner-bg);
    padding: 25px 35px;
    width: 90%; 
    border-radius: 14px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    display: flex;
    align-items: center;
    backdrop-filter: blur(5px);
    text-align: left;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.mockup-icon {
    font-size: 36px;
    margin-right: 25px;
    flex-shrink: 0;
}

.mockup-content p {
    font-weight: 500;
    font-size: 20px;
    color: var(--text-main);
    flex-grow: 1;
}

.dev-info {
    max-width: 900px;
}

.dev-details {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.pitch-text {
    font-size: 18px;
    line-height: 1.7;
}

.signature {
    margin-top: 20px;
    font-size: 14px;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
    padding-top: 15px;
}

.signature span:first-child {
    font-weight: 600;
    display: block;
}

.principles-grid {
    background-color: transparent;
    box-shadow: none;
    border: none;
    max-width: 100%;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
}

.grid-3 {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 25px;
}

.card-principle {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: var(--border-radius-main);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.03);
    border: 1px solid var(--border-color);
    transition: background-color 0.3s, border-color 0.3s;
}

.icon-large {
    font-size: 36px;
    display: block;
    margin-bottom: 10px;
}

.principle-title {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

.details-section {
    padding-top: 50px;
    padding-bottom: 50px;
}

.details-section .detail-card {
    padding: 25px;
    background-color: var(--background-light);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
    transition: background-color 0.3s, border-color 0.3s;
}

.detail-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: 15px;
}

.list-check {
    list-style-type: '— '; 
    padding-left: 20px;
    margin-left: 5px;
    font-size: 16px;
}

.list-check li { margin-bottom: 8px; }

.stack-card p, .url-card p {
    font-size: 15px;
    margin-bottom: 5px;
}

.big-status {
    font-size: 28px;
    font-weight: 700;
    margin-top: 10px;
    color: var(--primary-blue);
}

.small-status {
    font-size: 13px;
    color: var(--text-secondary);
}

.cta-section {
    background-color: var(--primary-blue);
    color: var(--card-bg);
    padding: 100px 0;
}

.cta-title {
    color: var(--card-bg);
}

.cta-subtitle {
    color: rgba(255, 255, 255, 0.8);
    font-size: 22px;
    margin-bottom: 40px;
}

.cta-section .button.secondary {
    background-color: var(--card-bg);
    color: var(--primary-blue);
    border-color: var(--card-bg);
}

.cta-section .button.secondary:hover {
    background-color: #f0f0f0;
}

.footer {
    text-align: center;
    padding: 30px 20px;
    font-size: 14px;
    color: var(--text-secondary);
    background-color: var(--background-light);
    border-top: 1px solid var(--border-color);
    transition: background-color 0.3s, border-color 0.3s;
}

@media (max-width: 900px) {
    .title-large { font-size: 52px; }
    .subtitle { font-size: 24px; }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    .large-card { padding: 30px; }
    .mockup-card { 
        height: 250px;
        max-width: 90%; 
    }
    .mockup-content {
        padding: 20px 25px;
    }
    .mockup-content p { font-size: 18px; }
    .cta-section { padding: 80px 0; }
}

@media (max-width: 500px) {
    .title-large { font-size: 38px; }
    .subtitle { font-size: 18px; }
    .header nav a { margin-left: 15px; }
    .button.large { padding: 15px 30px; font-size: 17px; }
}