@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&display=swap');

body {
    font-family: 'Montserrat', Arial, sans-serif;
    background: linear-gradient(135deg, #e0e7ff 0%, #f0fdfa 100%);
    margin: 0;
    color: #232946;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    font-size: 1.05em;
}

.container {
    max-width: 600px;
    margin: 36px auto 0 auto;
    background: #fff;
    border-radius: 22px;
    box-shadow: 0 8px 32px rgba(80, 80, 180, 0.10), 0 1.5px 8px rgba(80,80,180,0.08);
    padding: 32px 28px 24px 28px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 340px;
}

header {
    text-align: center;
    margin-bottom: 28px;
}

.logo {
    width: 70px;
    margin-bottom: 8px;
    filter: drop-shadow(0 2px 8px #6366f1aa);
}

.main-title {
    font-size: 2.3em;
    font-weight: 700;
    margin: 0;
    letter-spacing: 1px;
}

.brand-gradient {
    background: linear-gradient(90deg, #6366f1 10%, #06b6d4 90%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.08em;
    color: #6366f1;
    margin: 10px 0 0 0;
    font-weight: 500;
}

form#ai-form {
    margin-top: 18px;
}

.form-group {
    margin-bottom: 18px;
}

label {
    font-weight: 600;
    color: #232946;
    display: block;
    margin-bottom: 6px;
}

.form-note {
    font-size: 0.95em;
    color: #6b7280;
    font-weight: 400;
    margin-left: 4px;
}

select, textarea, input[type="file"] {
    width: 100%;
    padding: 10px 12px;
    border: 1.5px solid #c7d2fe;
    border-radius: 10px;
    font-size: 1em;
    margin-top: 4px;
    background: #f8fafc;
    transition: border 0.2s;
    outline: none;
    color: #232946;
    box-sizing: border-box;
}

select:focus, textarea:focus {
    border-color: #6366f1;
    background: #f0fdfa;
}

textarea {
    min-height: 70px;
    resize: vertical;
}

button[type="submit"], #download-watermark {
    background: linear-gradient(90deg, #6366f1 30%, #06b6d4 100%);
    color: #fff;
    font-weight: 700;
    border: none;
    border-radius: 10px;
    padding: 12px 0;
    width: 100%;
    font-size: 1.1em;
    margin-top: 10px;
    cursor: pointer;
    box-shadow: 0 2px 8px #6366f133;
    transition: background 0.2s, transform 0.15s;
    letter-spacing: 0.5px;
}

button[type="submit"]:hover, #download-watermark:hover {
    background: linear-gradient(90deg, #06b6d4 10%, #6366f1 90%);
    transform: translateY(-2px) scale(1.03);
}

#result {
    margin-top: 32px;
    background: linear-gradient(90deg, #f0fdfa 60%, #e0e7ff 100%);
    border-radius: 16px;
    padding: 18px 16px 14px 16px;
    box-shadow: 0 2px 8px #6366f122;
}

.result-title {
    font-size: 1.15em;
    font-weight: 700;
    color: #06b6d4;
    margin-bottom: 10px;
    text-align: center;
}

.result-images {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.result-image {
    min-height: 180px;
    min-width: 220px;
    background: #e0e7ff;
    border-radius: 12px;
    box-shadow: 0 1px 4px #6366f122;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 10px;
    overflow: hidden;
}

#result-url {
    margin-bottom: 8px;
}

#download-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 18px;
}

footer {
    margin-top: 32px;
    text-align: center;
    color: #6366f1;
    font-size: 1.05em;
    font-weight: 600;
    letter-spacing: 0.5px;
    background: none;
}

a {
    color: #06b6d4;
    text-decoration: none;
    transition: color 0.15s;
}

a:hover {
    color: #6366f1;
    text-decoration: underline;
}

/* Phần giới thiệu tác giả */
div[style*="text-align:center"] {
    margin-top: 28px !important;
    font-size: 1.05em !important;
    color: #06b6d4 !important;
    font-weight: 500;
}

/* Desktop styles (default) */
@media (min-width: 701px) {
    body {
        font-size: 1.05em;
    }
    .container {
        max-width: 600px;
        min-width: 340px;
    }
}

/* Mobile styles override using media query */
@media (max-width: 700px), (pointer: coarse) and (max-width: 900px) {
    body {
        font-size: 1em;
        padding: 0;
    }
    .container {
        max-width: 100vw;
        min-width: 0;
        padding: 8px 0 18px 0;
        border-radius: 0;
        box-shadow: none;
    }
    .main-title {
        font-size: 1.5em;
    }
    .subtitle {
        font-size: 1em;
    }
    .result-image {
        min-width: 120px;
        min-height: 100px;
    }
    .form-group {
        margin-bottom: 14px;
    }
    label, select, textarea, input, button {
        font-size: 1em;
        width: 100%;
        box-sizing: border-box;
    }
    #download-buttons button {
        width: 100%;
        margin-top: 8px;
        min-width: unset;
        padding: 11px 0;
    }
    .result-images {
        flex-direction: column;
        align-items: center;
    }
    .result-image {
        width: 100%;
        max-width: 100%;
    }
}

.container {
    display: inline-block;
    width: 100%;
    height: 100%;
}

.image-wrapper img {
    display: block;
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 24px #6366f144;
}

.ai-watermark {
    display: none;
}

.ai-watermark-by {
    position: absolute;
    right: 14px;
    bottom: 14px;
    z-index: 2;
    color: #fff;
    font-size: 0.98em;
    font-weight: 400;
    opacity: 0.85;
    border-radius: 6px;
    padding: 2px 10px;
    user-select: none;
    pointer-events: none;
    border: none;
}

#download-buttons {
    margin-top: 18px;
    display: flex;
    gap: 16px;
    justify-content: center;
    align-items: center;
}

#download-buttons button {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 11px 22px;
    border-radius: 8px;
    border: none;
    font-size: 1.04rem;
    font-weight: 600;
    background: linear-gradient(90deg, #6366f1 60%, #06b6d4 100%);
    color: #fff;
    box-shadow: 0 2px 10px rgba(99,102,241,0.10);
    cursor: pointer;
    transition: background 0.18s, transform 0.12s, box-shadow 0.18s;
    letter-spacing: 0.5px;
    outline: none;
    min-width: 210px;
    justify-content: center;
    border: 1.5px solid #a5b4fc;
}

#download-buttons button:hover {
    background: linear-gradient(90deg, #4f46e5 60%, #0ea5e9 100%);
    transform: translateY(-2px) scale(1.03);
    box-shadow: 0 4px 18px #6366f144;
}

#download-buttons button:active {
    transform: scale(0.98);
    background: linear-gradient(90deg, #6366f1 60%, #06b6d4 100%);
}

.ui-toggle {
    position: relative;
    display: flex;
    gap: 14px;
    justify-content: flex-end;
    align-items: center;
    margin-bottom: 10px;
    width: 100%;
    z-index: 10;
}

.ui-toggle button {
    opacity: 0.8;
    transition: opacity 0.18s, transform 0.15s;
    border-radius: 10px;
    background: #f0fdfa;
    border: 2px solid #e0e7ff;
    width: 46px;
    height: 46px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35em;
    box-shadow: 0 2px 8px #6366f122;
    margin: 0;
    padding: 0;
}
.ui-toggle button.active,
.ui-toggle button:hover {
    opacity: 1;
    background: #e0e7ff;
    border-color: #6366f1;
    transform: scale(1.10);
    box-shadow: 0 4px 16px #6366f133;
}
.ui-toggle button.active::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    transform: translateX(-50%);
    width: 18px;
    height: 4px;
    border-radius: 2px;
    background: linear-gradient(90deg, #6366f1 40%, #06b6d4 100%);
    display: block;
}

/* Ép giao diện desktop */
body.force-desktop {
    font-size: 1.05em !important;
}
body.force-desktop .container {
    max-width: 600px !important;
    min-width: 340px !important;
    border-radius: 22px !important;
    box-shadow: 0 8px 32px rgba(80, 80, 180, 0.10), 0 1.5px 8px rgba(80,80,180,0.08) !important;
    padding: 32px 28px 24px 28px !important;
}
body.force-desktop .main-title { font-size: 2.3em !important; }
body.force-desktop .subtitle { font-size: 1.08em !important; }
body.force-desktop .result-image { min-width: 220px !important; min-height: 180px !important; }

/* Ép giao diện mobile */
body.force-mobile {
    font-size: 1em !important;
}
body.force-mobile .container {
    max-width: 100vw !important;
    min-width: 0 !important;
    padding: 8px 0 18px 0 !important;
    border-radius: 0 !important;
    box-shadow: none !important;
}
body.force-mobile .main-title { font-size: 1.5em !important; }
body.force-mobile .subtitle { font-size: 1em !important; }
body.force-mobile .result-image { min-width: 120px !important; min-height: 100px !important; }
body.force-mobile #download-buttons button {
    width: 100% !important;
    margin-top: 8px !important;
    min-width: unset !important;
    padding: 11px 0 !important;
}
body.force-mobile .result-image { width: 100% !important; max-width: 100% !important; }